Search: id:A046699 Results 1-1 of 1 results found. %I A046699 %S A046699 1,1,2,2,3,4,4,4,5,6,6,7,8,8,8,8,9,10,10,11,12,12,12,13,14,14,15,16, %T A046699 16,16,16,16,17,18,18,19,20,20,20,21,22,22,23,24,24,24,24,25,26,26, %U A046699 27,28,28,28,29,30,30,31,32,32,32,32,32,32,33,34,34,35,36,36,36,37 %N A046699 a(1) = a(2) = 1, a(n) = a(n - a(n-1)) + a(n-1 - a(n-2)) if n > 2. %C A046699 Ignoring first term, this is the Meta-Fibonacci sequence for s=0. - Frank Ruskey (http://www.cs.uvic.ca/~ruskey/) and Chris Deugau (deugaucj(AT)uvic.ca) %C A046699 Except for first term, n occurs A001511(n) times. - Franklin T. Adams-Watters, Oct 22 2006 %D A046699 Sequence proposed by Reg Allenby. %D A046699 B. Jackson and F. Ruskey, Meta-Fibonacci Sequences, Binary Trees and Extremal Compact Codes, Electronic Journal of Combinatorics, 13 (2006), #R26, 13 pages. %D A046699 S. Vajda, Fibonacci and Lucas Numbers and the Golden Section, Wiley, 1989, see p. 129. %D A046699 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 129. %H A046699 T. D. Noe, Table of n, a(n) for n=1..1000 %H A046699 C. Deugau and F. Ruskey, Complete k-ary Trees and Generalized Meta-Fibonacci Sequences, J. Integer Seq., Vol. 12. [This is a later version than that in the GenMetaFib.html link] %H A046699 Joerg Arndt, Fxtbook %H A046699 C. Deugau and F. Ruskey, Complete k-ary Trees and Generalized Meta-Fibonacci Sequences %H A046699 B. Jackson and F. Ruskey, Meta-Fibonacci Sequences, Binary Trees and Extremal Compact Codes %H A046699 Index entries for Hofstadter-type sequences %F A046699 First differences seem to be A079559. - Vladeta Jovovic (vladeta(AT)eunet.rs), Nov 30 2003. This is correct and not too hard to prove, giving the generating function x + x^2(1+x)(1+x^3)(1+x^7)(1+x^15).../(1-x). - Paul Boddington (psb(AT)maths.warwick.ac.uk), Jul 30 2004 %F A046699 G.f. x + x^2/(1-x) * Product_{n=1}^{infinity} (1 + x^(2^n-1)) - Frank Ruskey (http://www.cs.uvic.ca/~ruskey/) and Chris Deugau (deugaucj(AT)uvic.ca) %F A046699 for n>=1, a(n)=w(n-1) where w(n) is the least k such that 2^n divides (2k)! - Benoit Cloitre (benoit7848c(AT)orange.fr), Jan 19 2007 %p A046699 a := proc(n) option remember; if n <= 1 then return 1 end if; if n <= 2 then return 2 end if; return add(a(n - i + 1 - a(n - i)), i = 1 .. 2) end proc - Frank Ruskey (http://www.cs.uvic.ca/~ruskey/) and Chris Deugau (deugaucj(AT)uvic.ca) %o A046699 (PARI) a(n)=if(n<0,1,s=1;while((2*s)!%2^(n-1)>0,s++);s) - Benoit Cloitre (benoit7848c(AT)orange.fr), Jan 19 2007 %Y A046699 Cf. A005185. %Y A046699 Sequence in context: A029111 A092038 A159481 this_sequence A102548 A004001 A086841 %Y A046699 Adjacent sequences: A046696 A046697 A046698 this_sequence A046700 A046701 A046702 %K A046699 nonn,nice %O A046699 1,3 %A A046699 R. K. Guy (rkg(AT)cpsc.ucalgary.ca) %E A046699 There are good arguments for dropping the first term, but I am reluctant to do this for a sequence with so many references. - N. J. A. Sloane (njas(AT)research.att.com), Oct 22 2006 Search completed in 0.001 seconds