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 A142703 #7 Oct 04 2015 01:49:01
%S A142703 1,1,8,54,496,5500,71952,1084328,18500480,352526544,7420540480,
%T A142703 171007474528,4282272360192,115785275702720,3361891345761536,
%U A142703 104330298643927680,3446150079670054912,120716332862675408128
%N A142703 a(n) = 2*(n-1)*( a(n-1)+a(n-2) ) starting a(1)=a(2)=1.
%p A142703 A142703 := proc(n) if n <=2 then 1 ; else 2*(n-1)*( procname(n-1)+procname(n-2)) ; end if; end proc: # _R. J. Mathar_, May 26 2011
%t A142703 Clear[a, b, n, k] k = 2; b[0] = 0; b[n_] := b[n] = b[n - 1] + k; a[0] = 1; a[1] = 1; a[n_] := a[n] = b[n]*(a[n - 1] + a[n - 2]); Table[a[n], {n, 0, 20}]
%Y A142703 Cf. A002467, A000045.
%K A142703 nonn,easy
%O A142703 1,3
%A A142703 _Roger L. Bagula_ and _Gary W. Adamson_, Sep 24 2008