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 A188679 #17 Sep 26 2019 11:32:33 %S A188679 1,10,235,7291,252316,9270325,353892421,13874930821,554792522662, %T A188679 22521121103287,925224047453512,38381686035811912,1605078750713101912, %U A188679 67578873844051699048,2861782692234129345448,121795323921169907086504 %N A188679 Partial sums of binomial(3n,n)^2. %H A188679 Seiichi Manyama, <a href="/A188679/b188679.txt">Table of n, a(n) for n = 0..604</a> %F A188679 a(n) = sum(C(3k,k)^2, k=0..n). %F A188679 Recurrence: 4*(2*n^2+7*n+6)^2 * a(n+2) -(745*n^4+4486*n^3+10093*n^2 +10056*n+3744) * a(n+1) +9*(9*n^2+27*n+20)^2 * a(n) = 0. %F A188679 G.f.: (1-x)^(-1)*F(1/3,1/3,2/3,2/3;1/2,1/2,1;729*x/16), where F(a1,a2,a3,a4;b1,b2,b3;z) is a hypergeometric series. %F A188679 a(n) ~ 3^(6*n+7)/(713*Pi*n*2^(4*n+2)). - _Vaclav Kotesovec_, Aug 06 2013 %t A188679 Table[Sum[Binomial[3k,k]^2,{k,0,n}],{n,0,20}] %t A188679 Accumulate[Table[Binomial[3n,n]^2,{n,0,20}]] (* _Harvey P. Dale_, Sep 26 2019 *) %o A188679 (Maxima) makelist(sum(binomial(3*k,k)^2,k,0,n),n,0,20); %Y A188679 Cf. A005809, A001764, A188676, A104859, A188678, A188680, A188681, A188682, A188683, A188684, A188685, A188686, A188687. %K A188679 nonn,easy %O A188679 0,2 %A A188679 _Emanuele Munarini_, Apr 08 2011