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 A000658 #27 Sep 09 2015 23:51:09
%S A000658 1,4,68,1732,51076,1657904,57793316,2117525792,80483121028,
%T A000658 3147565679824,125937573689968,5133632426499152,212530848994367524,
%U A000658 8914634034287235856,378138515326996979168,16196097181014298854032
%N A000658 Strehl's sequence "C_n^(3)".
%D A000658 Volker Strehl, Binomial identities - combinatorial and algorithmic aspects. Trends in discrete mathematics. Discrete Math. 136 (1994), no. 1-3, 309-346.
%H A000658 Reinhard Zumkeller, <a href="/A000658/b000658.txt">Table of n, a(n) for n = 0..100</a>
%H A000658 Vaclav Kotesovec, <a href="/A000658/a000658.txt">Recurrence (of order 6)</a>
%F A000658 Sum binomial(n, k)^2 * binomial(2k, k)^2 * binomial(2k, n-k); k=0..n.
%F A000658 a(n) ~ 7^(2*n+5/2) / (20 * sqrt(15) * Pi^2 * n^2). - _Vaclav Kotesovec_, Mar 09 2014
%p A000658 A000658:=n->add(binomial(n,k)^2*binomial(2*k,k)^2*binomial(2*k,n-k), k=0..n): seq(A000658(n), n=0..15); # _Wesley Ivan Hurt_, Sep 19 2014
%t A000658 Table[Sum[Binomial[n,k]^2 Binomial[2k,k]^2 Binomial[2k,n-k],{k,0,n}], {n,0,25}] (* _Harvey P. Dale_, Oct 19 2011 *)
%o A000658 (PARI) a(n)=sum(k=1,n, binomial(n, k)^2 * binomial(2k, k)^2 * binomial(2k, n-k)) \\ _Charles R Greathouse IV_, Sep 19 2014
%o A000658 (Haskell)
%o A000658 a000658 n = sum $ map c3 [0..n] where
%o A000658 c3 k = (a007318' n k)^2 * (a007318' (2*k) k)^2 * a007318' (2*k) (n-k)
%o A000658 -- _Reinhard Zumkeller_, May 20 2015
%Y A000658 Third row of array A094424.
%Y A000658 Cf. A007318.
%K A000658 nonn,easy,nice
%O A000658 0,2
%A A000658 _Don Knuth_