OFFSET
0,5
COMMENTS
FORMULA
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]
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: 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
MATHEMATICA
A056857[n_, c_] := If[n <= c, 0, BellB[n - 1 - c] Binomial[n - 1, c]];
a[n_] := A078939[n + 1, 3];
a /@ Range[0, 19] (* Jean-François Alcover, Mar 24 2020, after R. J. Mathar *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gottfried Helms, Apr 08 2007
EXTENSIONS
More terms from R. J. Mathar, May 30 2008
STATUS
approved