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 A192060 #6 Jun 02 2025 04:11:22 %S A192060 1,0,-3,15,42,-2895,54417,-251160,-32268603,1859064495,-56137896318, %T A192060 -300966155655,194418466667697,-17000801954550960,829654990634826717, %U A192060 8111862191577165855,-7601061861134689474758,1057729211267718608758065 %N A192060 E.g.f. cos(cos(x)-1) (even part). %F A192060 a(n):=2*(sum(k=0..n, ((-1)^(k)*sum(j=1..2*k, ((sum(i=0..(j-1)/2, (j-2*i)^(2*n)*binomial(j,i)))*binomial(2*k,j)*(-1)^(n-j))/2^j))/(2*k)!)), n>0, a(0)=1. %o A192060 (Maxima) %o A192060 a(n):=if n=0 then 1 else 2*(sum(((-1)^(k)*sum(((sum((j-2*i)^(2*n)*binomial(j,i),i,0,(j-1)/2))*binomial(2*k,j)*(-1)^(n-j))/2^j,j,1,2*k))/(2*k)!,k,0,n)); %K A192060 sign %O A192060 0,3 %A A192060 _Vladimir Kruchinin_, Jun 21 2011