Search: id:A001629 Results 1-1 of 1 results found. %I A001629 M1377 N0537 %S A001629 0,0,1,2,5,10,20,38,71,130,235,420,744,1308,2285,3970,6865,11822,20284, %T A001629 34690,59155,100610,170711,289032,488400,823800,1387225,2332418, %U A001629 3916061,6566290,10996580,18394910,30737759,51310978,85573315 %N A001629 Fibonacci numbers convolved with themselves. %C A001629 Number of elements in all subsets of {1,2,...,n-1} with no consecutive integers. Example: a(5)=10 because the subsets of {1,2,3,4} that have no consecutive elements, i.e. {},{1},{2},{3},{4},{1,3},{1,4}, {2,4}, the total number of elements is 10. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 10 2003 %C A001629 If g is either of the real solutions to x^2-x-1=0, g'=1-g is the other one and phi is any 2 X 2-matricial solution to the same equation, not of the form gI or g'I, then Sum'_{i+j=n-1}g^i phi^j=F_n+(A001629(n)-A001629(n-1)g')(phi-g'I), where i,j>=0,F_n is the n-th Fibonacci number and I is the 2 X 2 identity matrix... - Michele Dondi (blazar(AT)lcm.mi.infn.it), Apr 06 2004 %C A001629 Number of 3412-avoiding involutions containing exactly one subsequence of type 321. %C A001629 Number of binary sequences of length n with exactly one pair of consecutive 1's. - George J. Schaeffer (gschaeff(AT)andrew.cmu.edu), Sep 02 2004 %C A001629 For this sequence the n-th term is given by (nF(n+1)-F(n)+nF(n-1))/5 where F(n) is the n-th Fibonacci number. - Mrs J. P. Shiwalkar and M. N. Deshpande (dpratap_ngp(AT)sancharnet.in), Apr 20 2005 %C A001629 If an unbiased coin is tossed n times then there are 2^n possible strings of H and T.Out of these, number of strings with exactly one 'HH'is given by a(n)where a(n) denotes n-th term of this sequence - Mrs J. P. Shiwalkar and M. N. Deshpande (dpratap_ngp(AT)sancharnet.in), May 04 2005 %C A001629 a(n) = half the number of horizontal dominoes in all domino tilings of a horizontally aligned 2 X n rectangle; a(n+1) = the number of vertical dominoes in all domino tilings of a horizontally aligned 2 X n rectangle; thus 2*a(n)+a(n+1)=n*F(n+1) = the number of dominoes in all domino tilings of a 2 X n rectangle, where F=A000045, the Fibonacci sequence. - Roberto Tauraso (tauraso(AT)mat.uniroma2.it), May 02 2005; Graeme McRae (g_m(AT)mcraefamily.com), Jun 02 2006 %C A001629 a(n+1)=((-I)^(n-1))*diff(S(n,x),x)|_{x=I}, n>=1. First derivative of Chebyshev S-polynomials evaluated at x=I (imaginary unit) multiplied by (-I)^(n-1). See A049310 for the S-polynomials. W. Lang, Apr 04 2007. %D A001629 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A001629 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001629 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %D A001629 V. E. Hoggatt, Jr. and M. Bicknell-Johnson, Fibonacci convolution sequences, Fib. Quart., 15 (1977), 117-122. %D A001629 Thomas Koshy, Fibonacci and Lucas Numbers with Applications, Chapter 15, page 187, "Hosoya's Triangle" %D A001629 J. Riordan, Combinatorial Identities, Wiley, 1968, p. 101. %D A001629 S. Vajda, Fibonacci and Lucas numbers and the Golden Section, Ellis Horwood Ltd., Chichester, 1989, p. 183, Nr.(98). %H A001629 T. D. Noe, Table of n, a(n) for n=0..500 %H A001629 Index entries for sequences related to linear recurrences with constant coefficients %H A001629 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %H A001629 S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %H A001629 P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5. %H A001629 E. S. Egge, Restricted 3412-Avoiding Involutions, p. 16. %H A001629 T. Mansour, Generalization of some identities involving the Fibonacci numbers %H A001629 P. Moree, Convoluted convolved Fibonacci numbers %H A001629 Pieter Moree, Convoluted Convolved Fibonacci Numbers, Journal of Integer Sequences, Vol. 7 (2004), Article 04.2.2. %H A001629 S. Klavzar, On median nature and enumerative properties of Fibonacci-like cubes, Disc. Math. 299 (2005), 145-153. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 05 2008] %F A001629 G.f.: x^2/(1-x-x^2)^2; a(n)=2*a(n-1)+a(n-2)-2*a(n-3)-a(n-4), n>3; a(n)=sum(F(k)F(n-k)), k=0..n where F=A000045 (the Fibonacci sequence). %F A001629 a(n+1) = sum(A007895(i), 0 <= i <= F(n)), where F = A000045, the Fibonacci sequence - Claude Lenormand (claude.lenormand(AT)free.fr), Feb 04 2001 %F A001629 a(n)=sum((k+1)*binomial(n-k-1, k+1), k=0..floor(n/2)-1). - Emeric Deutsch (deutsch(AT)duke.poly.edu), Nov 15 2001 %F A001629 a(n)=floor( (1/5)*(n-1/sqrt(5))*phi^n + 1/2 ) where phi=(1+sqrt(5))/2 is the golden ratio. - Benoit Cloitre (benoit7848c(AT)orange.fr), Jan 05 2003 %F A001629 a(n)=a(n-1)+A010049(n-1) for n>0. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Dec 10 2003 %F A001629 a(n)=sum{k=0..floor((n-2)/2), (n-k-1)binomial(n-k-2, k)} - Paul Barry (pbarry(AT)wit.ie), Jan 25 2005 %F A001629 a(n)= ((n-1)*F(n)+2*n*F(n-1))/5, F(n)=A000045(n) (see Vajda reference) %F A001629 F'(n, 1), the first derivative of the n-th Fibonacci polynomial evaluated at 1. - T. D. Noe (noe(AT)sspectra.com), Jan 18 2006 %F A001629 a(n)=a(n-1)+a(n-2)+F(n-1), where F=A000045, the Fibonacci sequence. - Graeme McRae (g_m(AT)mcraefamily.com), Jun 02 2006 %F A001629 a(n)=(1/5)(n-1/sqrt(5))((1+sqrt(5))/2)^n + (1/5)(n+1/sqrt(5))((1-sqrt(5))/ 2)^n - Graeme McRae (g_m(AT)mcraefamily.com), Jun 02 2006 %F A001629 a(n) = A055244(n-1) - F(n-2). Example: a(6) = 20 = A055244(5) - F(3) = (23 - 3). - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 27 2007 %F A001629 a(n) = sum of (n-1)-th row terms of triangle A134510; e.g., a(6) = 20 = (8 + 5 + 5 + 1 + 1). - Gary W. Adamson (qntmpkt(AT)yahoo.com), Oct 28 2007 %F A001629 Starting (1, 2, 5, 10, 20, 38,...), = row sums of triangle A134836. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Nov 12 2007 %F A001629 a(n) = term (1,3) in the 4x4 matrix [2,1,0,0; 1,0,1,0; -2,0,0,1; -1,0, 0,0]^n. [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 01 2008] %e A001629 sage: taylor( mul((x^2)/(1-x^2-x^4) for i in xrange(0,2)),x,0,69)#solution> > x^4 + 2*x^6 + 5*x^8 + 10*x^10 + 20*x^12 + 38*x^14 + 71*x^16 + 130*x^18 + 235*x^20 + 420*x^22 + 744*x^24 + 1308*x^26 + 2285*x^28 + 3970*x^30 + 6865*x^32 + 11822*x^34 + 20284*x^36 + etc... [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 01 2009] %p A001629 A001629:=1/(z**2+z-1)**2; [Conjectured by S. Plouffe in his 1992 dissertation.] %p A001629 (Maple) a := n -> (Matrix(4, (i,j)-> if (i=j-1) then 1 elif j=1 then [2, 1, -2, -1][i] else 0 fi)^n)[1,3] ; seq (a(n), n=0..34); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Aug 01 2008] %t A001629 Table[Sum[Binomial[n - i, i]*i, {i, 0, n}], {n, 0, 34}] [From Geoffrey Critzer (critzer.geoffrey(AT)usd443.org), May 04 2009] %o A001629 (Other) sage: taylor( mul((x^2)/(1-x^2-x^4) for i in xrange(0,2)),x,0, 69)# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 01 2009] %Y A001629 a(n)= A037027(n-1, 1), n >= 1, (Fibonacci convolution triangle). Cf. A000045, A001628. %Y A001629 Row sums of triangle A058071. %Y A001629 Cf. A010049. %Y A001629 First differences of A006478. %Y A001629 Cf. A055244. %Y A001629 Cf. A134510. %Y A001629 Cf. A134836. %Y A001629 Sequence in context: A000712 A032442 A102688 this_sequence A159230 A068034 A084215 %Y A001629 Adjacent sequences: A001626 A001627 A001628 this_sequence A001630 A001631 A001632 %K A001629 nonn,easy,nice %O A001629 0,4 %A A001629 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.002 seconds