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A182933
Generalized Bell numbers based on the rising factorial powers; square array read by antidiagonals.
5
1, 1, 1, 1, 1, 1, 1, 2, 3, 1, 1, 5, 27, 13, 1, 1, 15, 409, 778, 73, 1, 1, 52, 9089, 104149, 37553, 501, 1, 1, 203, 272947, 25053583, 57184313, 2688546, 4051, 1, 1, 877, 10515147, 9566642254, 192052025697, 56410245661, 265141267, 37633, 1
OFFSET
0,8
COMMENTS
These numbers are related to the generalized Bell numbers based on the falling factorial powers (A090210).
The square array starts for n>=0, k>=0:
n\k=0,1,.. A000012,A000262,A182934,...
0: A000012: 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
1: A000110: 1, 1, 2, 5, 15, 52, 203, 877, 4140, ...
2: A094577: 1, 3, 27, 409, 9089, 272947, 10515147, ...
3: A182932: 1, 13, 778, 104149, 25053583, 9566642254, ...
4: : 1, 73, 37553, 57184313, 192052025697, ...
5: : 1, 501, 2688546, 56410245661, ...
6: .... : 1, 4051, 265141267, 89501806774945, ...
FORMULA
Let r_k = [n+1,...,n+1] (k occurrences of n+1), s_k = [1,...,1,2] (k-1 occurrences of 1) and F_k the generalized hypergeometric function of type k_F_k, then a(n,k) = exp(-1)*n!^k*F_k(r_k, s_k | 1).
Let B_{n}(x) = sum_{j>=0}(exp((j+n-1)!/(j-1)!*x-1)/j!) then a(n,k) = k! [x^k] series(B_{n}(x)), where [x^k] denotes the coefficient of x^k in the Taylor series for B_{n}(x).
MAPLE
A182933_AsSquareArray := proc(n, k) local r, s, i;
r := [seq(n+1, i=1..k)]; s := [seq(1, i=1..k-1), 2];
exp(-x)*n!^k*hypergeom(r, s, x); round(evalf(subs(x=1, %), 99)) end:
seq(lprint(seq(A182933_AsSquareArray(n, k), k=0..6)), n=0..6);
MATHEMATICA
a[n_, k_] := Exp[-1]*n!^k*HypergeometricPFQ[ Table[n+1, {k}], Append[ Table[1, {k-1}], 2], 1.]; Table[ a[n-k, k] // Round , {n, 0, 8}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Jul 29 2013 *)
KEYWORD
nonn,tabl
AUTHOR
Peter Luschny, Mar 29 2011
STATUS
approved