# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a193045 Showing 1-1 of 1 %I A193045 #8 Jun 13 2015 00:53:55 %S A193045 0,1,1,3,8,21,49,105,210,399,729,1293,2242,3821,6427,10703,17690, %T A193045 29073,47579,77621,126340,205291,333171,540233,875428,1417961,2295989, %U A193045 3716875,6016140,9736669,15756869,25498033,41259862,66763351,108029197 %N A193045 Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments. %C A193045 The titular polynomials are defined recursively: p(n,x)=x*p(n-1,x)+n(-1+n^2)/6, with p(0,x)=1. For an introduction to reductions of polynomials by substitutions such as x^2->x+1, see A192232 and A192744. %H A193045 Index entries for linear recurrences with constant coefficients, signature (5,-9,6,1,-3,1) %F A193045 a(n)=5*a(n-1)-9*a(n-2)+6*a(n-3)+a(n-4)-3*a(n-5)+a(n-6). %F A193045 G.f.: -x*(1-4*x+7*x^2-4*x^3+x^4) / ( (x^2+x-1)*(x-1)^4 ). - _R. J. Mathar_, May 12 2014 %t A193045 (See A193044.) %Y A193045 Cf. A192232, A192744, A192951, A193044. %K A193045 nonn %O A193045 0,4 %A A193045 _Clark Kimberling_, Jul 15 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE