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 A129333 #10 Mar 24 2020 08:30:47 %S A129333 0,0,0,1,16,200,2320,26460,303968,3557904,42676320,526076100, %T A129333 6673368240,87148818328,1171554274800,16206294360620,230561544221120, %U A129333 3371256518888480,50628767109223872,780358333403627796 %N A129333 Fourth column of PE^4. %C A129333 Base matrix is in A011971; second power is in A078937; third power is in A078938; fourth power is in A078939. %F A129333 PE=exp(matpascal(5))/exp(1); A = PE^4; a(n)= A[ n,4 ] with exact integer arithmetic: PE=exp(matpascal(5)-matid(6)); A = PE^4; a(n)=A[ n,4] %p A129333 A056857 := proc(n,c) combinat[bell](n-1-c)*binomial(n-1,c) ; end: A078937 := proc(n,c) add( A056857(n,k)*A056857(k+1,c),k=0..n) ; end: A078938 := proc(n,c) add( A078937(n,k)*A056857(k+1,c),k=0..n) ; end: A078939 := proc(n,c) add( A078938(n,k)*A056857(k+1,c),k=0..n) ; end: A129333 := proc(n) A078939(n+1,3) ; end: seq(A129333(n),n=0..25) ; # _R. J. Mathar_, May 30 2008 %t A129333 A056857[n_, c_] := If[n <= c, 0, BellB[n - 1 - c] Binomial[n - 1, c]]; %t A129333 A078937[n_, c_] := Sum[A056857[n, k] A056857[k + 1, c], {k, 0, n}]; %t A129333 A078938[n_, c_] := Sum[A078937[n, k] A056857[k + 1, c], {k, 0, n}]; %t A129333 A078939[n_, c_] := Sum[A078938[n, k] A056857[k + 1, c], {k, 0, n}]; %t A129333 a[n_] := A078939[n + 1, 3]; %t A129333 a /@ Range[0, 19] (* _Jean-François Alcover_, Mar 24 2020, after _R. J. Mathar_ *) %Y A129333 Cf. A056857, A078937, A078938, A078944, A078945, A000110. %Y A129333 Cf. A078937, A078938, A129323, A129324, A129325, A027710. %Y A129333 Cf. A129327, A129328, A129329, A078944, A129331, A129332, A129333. %K A129333 nonn,easy %O A129333 0,5 %A A129333 _Gottfried Helms_, Apr 08 2007 %E A129333 More terms from _R. J. Mathar_, May 30 2008