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 A014151 #28 Jul 08 2025 02:53:12 %S A014151 1,4,11,27,66,170,471,1398,4381,14282,47897,164012,570639,2010678, %T A014151 7158569,25709157,93020112,338736224,1240496193,4565563209, %U A014151 16878057692,62644246662,233346693759,872045012633,3268643350608,12285088109136,46288732360369,174813127020311,661606223839322 %N A014151 Apply partial sum operator thrice to Catalan numbers. %H A014151 Vincenzo Librandi, <a href="/A014151/b014151.txt">Table of n, a(n) for n = 0..1000</a> %F A014151 D-finite with recurrence: n*(n+1)*a(n) = 2*n*(3*n+1)*a(n-1) - (9*n^2+7*n-4)*a(n-2) + 2*(n+1)*(2*n+1)*a(n-3). - _Vaclav Kotesovec_, Oct 07 2012 %F A014151 a(n) ~ 2^(2*n+6)/(27*sqrt(Pi)*n^(3/2)). - _Vaclav Kotesovec_, Oct 07 2012 %F A014151 G.f.: C(x)/(1-x)^3, where C(x) is g.f. of Catalan numbers. - _Vladimir Kruchinin_, Oct 18 2016 %F A014151 a(n) = Sum_{k=0..n} binomial(n+3,k+3) * r(k), r(k) = A005043(k). - _Vladimir Kruchinin_, Oct 18 2016 %t A014151 Flatten[{1, RecurrenceTable[{n*(n+1)*a[n] == 2*n*(3*n+1)*a[n-1] - (9*n^2+7*n-4)*a[n-2] + 2*(n+1)*(2*n+1)*a[n-3],a[1]==4,a[2]==11,a[3]==27},a,{n,100}]}] %o A014151 (PARI) %o A014151 sm(v)={my(s=vector(#v));s[1]=v[1];for(n=2,#v,s[n]=v[n]+s[n-1]);s;} %o A014151 C(n)=binomial(2*n,n)/(n+1); %o A014151 sm(sm(sm(vector(66,n,C(n-1))))) %o A014151 /* _Joerg Arndt_, May 04 2013 */ %Y A014151 Cf. A000108, A014137, A005043 %K A014151 nonn,easy %O A014151 0,2 %A A014151 _N. J. A. Sloane_