Search: id:A030195 Results 1-1 of 1 results found. %I A030195 %S A030195 0,1,3,12,45,171,648,2457,9315,35316,133893,507627,1924560,7296561, %T A030195 27663363,104879772,397629405,1507527531,5715470808,21668995017, %U A030195 82153397475,311467177476,1180861724853,4476986706987,16973545295520 %N A030195 a(n) = 3*a(n-1)+3*a(n-2), a(0)=0, a(1)=1. %C A030195 Scaled Chebyshev U-polynomials evaluated at I*sqrt(3)/2. %D A030195 A. F. Horadam, Special properties of the sequence w_n(a,b; p,q), Fib. Quart., 5.5 (1967), 424-434. Case n->n+1, a=0,b=1; p=q=3. %D A030195 Thomas Koshy, "Fibonacci and Lucas Numbers with Applications", Wiley, 2001, p. 471. %D A030195 W. Lang, On polynomials related to powers of the generating function of Catalan's numbers, Fib. Quart. 38,5 (2000) 408-419; Eqs. (39), (41) and (45), rhs, m=3. %H A030195 Index entries for sequences related to linear recurrences with constant coefficients %H A030195 Tanya Khovanova, Recursive Sequences %H A030195 Index entries for sequences related to Chebyshev polynomials. %F A030195 a(n)=(-I*sqrt(3))^n*U(n, I*sqrt(3)/2), g.f.: 1/(1-3*x-3*x^2). %F A030195 a(n) = sum(3^(n-k)*binomial(n-k, k), k=0..floor(n/2)). - Emeric Deutsch (deutsch(AT)duke.poly.edu), Nov 14 2001 %F A030195 a(n) = [p^(n+1) - q^(n+1)]/(sqrt 21); p = (3 + sqrt 21)/2, q = (3 - sqrt 21)/2. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 02 2003 %F A030195 For n > 0, a(n) = Sum_{k=0..n-1} (2^k)*A063967(n-1,k) - Gerald McGarvey (gerald.mcgarvey(AT)comcast.net), Jul 23 2006 %F A030195 a(n+1)=Sum_{k, 0<=k<=n}2^k*A063967(n,k) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 03 2006 %F A030195 G.f.: x/(1-3x-3x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 19 2008] %t A030195 CoefficientList[Series[1/(1-3x-3x^2), {x, 0, 25}], x] - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 22 2007 %o A030195 (Other) sage: [lucas_number1(n,3,-3) for n in xrange(0, 25)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 22 2009] %Y A030195 Equals round(A085480(n)/sqrt(21)). %Y A030195 Sequence in context: A062561 A128593 A085481 this_sequence A114515 A151162 A094547 %Y A030195 Adjacent sequences: A030192 A030193 A030194 this_sequence A030196 A030197 A030198 %K A030195 nonn %O A030195 0,3 %A A030195 Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de) %E A030195 Edited by Ralf Stephan, Aug 02 2004 %E A030195 I simplified the definition. As a result the offsets in some of the formulae may need to shifted by 1. - N. J. A. Sloane (njas(AT)research.att.com), Apr 01, 2006. Search completed in 0.002 seconds