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 A089470 #5 Mar 30 2012 18:36:39 %S A089470 1,1,4,29,303,4108,68165,1334403,30056112,764920823,21694511367, %T A089470 678288426792,23173084581845,858785085529061,34311202499100416, %U A089470 1470080434980994825,67236889676684657943,3269565144147886318168 %N A089470 Self-convolution of this sequence is equal to its hyperbinomial transform and results in A089471. %C A089470 See A088956 for the definition of the hyperbinomial transform. %F A089470 A089471(n) = sum(k=1, n, a(k)*a(n-k)); A089471(n) = sum(k=0, n, (n-k+1)^(n-k-1)*binomial(n, k)*a(k)). %e A089470 The self-convolution at n=4: 303*1+29*1+4*4+1*29+1*303 = 680 = A089471(4) and equals the hyperbinomial transform at n=4: 125*1+64*1+18*4+4*29+1*303 = 680 = A089471(4). %Y A089470 Cf. A089471, A088956. %K A089470 nonn %O A089470 0,3 %A A089470 _Paul D. Hanna_, Nov 07 2003