This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A193047 #8 Jun 13 2015 00:53:55 %S A193047 0,1,2,19,102,377,1104,2777,6282,13155,25998,49153,89792,159681, %T A193047 278034,476131,804790,1346457,2234768,3686201,6051290,9897491, %U A193047 16143262,26275009,42698112,69304897,112393634,182155507,295080582,477850745 %N A193047 Coefficient of x in the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments. %C A193047 The titular polynomials are defined recursively: p(n,x)=x*p(n-1,x)+n^4, 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 A193047 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (6,-14,15,-5,-4,4,-1). %F A193047 a(n)=6*a(n-1)-14*a(n-2)+15*a(n-3)-5*a(n-4)-4*a(n-5)+4*a(n-6)-a(n-7). %F A193047 G.f.: -x*(-1+4*x-21*x^2-x^3-6*x^4+x^5) / ( (x^2+x-1)*(x-1)^5 ). - _R. J. Mathar_, May 12 2014 %t A193047 (See A193046.) %Y A193047 Cf. A192232, A192744, A192951, A193046. %K A193047 nonn %O A193047 0,3 %A A193047 _Clark Kimberling_, Jul 15 2011