A129329 Fourth column of PE^3.
0, 0, 0, 1, 12, 120, 1140, 10815, 104496, 1037484, 10627560, 112508550, 1231481460, 13933510734, 162864103584, 1965078765195, 24453461392080, 313549334233440, 4138796594051568, 56188737057169593, 783876449182595400
Offset: 0
Crossrefs
Programs
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Maple
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: A129329 := proc(n) A078938(n+1,3) ; end: seq(A129329(n),n=0..27) ; # R. J. Mathar, May 30 2008
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Mathematica
A056857[n_, c_] := If[n <= c, 0, BellB[n - 1 - c] Binomial[n - 1, c]]; A078937[n_, c_] := Sum[A056857[n, k] A056857[k + 1, c], {k, 0, n}]; A078938[n_, c_] := Sum[A078937[n, k] A056857[k + 1, c], {k, 0, n}]; a[n_] := A078938[n + 1, 3]; a /@ Range[0, 20] (* Jean-François Alcover, Mar 24 2020, after R. J. Mathar *)
Formula
PE=exp(matpascal(5))/exp(1); A = PE^3; a(n)= A[ n,4 ] with exact integer arithmetic: PE=exp(matpascal(5)-matid(6)); A = PE^3; a(n)=A[ n,4]
E.g.f.: (x^3/6) * exp(3 * (exp(x) - 1)). - Ilya Gutkovskiy, Jul 11 2020
Extensions
More terms from R. J. Mathar, May 30 2008
Comments