login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A182931 Generalized Bell numbers; square array read by ascending antidiagonals, A(n, k) for n >= 0 and k >= 1. 0
1, 1, 1, 2, 0, 1, 5, 1, 0, 1, 15, 1, 0, 0, 1, 52, 4, 1, 0, 0, 1, 203, 11, 1, 0, 0, 0, 1, 877, 41, 1, 1, 0, 0, 0, 1, 4140, 162, 11, 1, 0, 0, 0, 0, 1, 21147, 715, 36, 1, 1, 0, 0, 0, 0, 1, 115975, 3425, 92, 1, 1, 0, 0, 0, 0, 0, 1, 678570, 17722, 491, 36, 1, 1, 0, 0, 0, 0, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..78.

E. A. Enneking and J. C. Ahuja, Generalized Bell numbers, Fib. Quart., 14 (1976), 67-73.

Peter Luschny, Set partitions

FORMULA

E.g.f.: exp(exp(x)*(1-Gamma(k,x)/Gamma(k))); Gamma(k,x) the incomplete Gamma function.

EXAMPLE

Array starts:

[k=      1       2       3       4       5]

[n=0]    1,      1,      1,      1,      1,

[n=1]    1,      0,      0,      0,      0,

[n=2]    2,      1,      0,      0,      0,

[n=3]    5,      1,      1,      0,      0,

[n=4]   15,      4,      1,      1,      0,

[n=5]   52,     11,      1,      1,      1,

[n=6]  203,     41,     11,      1,      1,

[n=7]  877,    162,     36,      1,      1,

[n=8] 4140,    715,     92,     36,      1,

   A000110,A000296,A006505,A057837,A057814, ...

MAPLE

egf := k -> exp(exp(x)*(1-GAMMA(k, x)/GAMMA(k)));

T := (n, k) -> n!*coeff(series(egf(k), x, n+1), x, n):

seq(print(seq(T(n, k), k=1..8)), n=0..8);

MATHEMATICA

egf[k_] := Exp[Exp[x] (1 - Gamma[k, x]/Gamma[k])];

T[n_, k_] := n! SeriesCoefficient[egf[k], {x, 0, n}];

Table[T[n-k+1, k], {n, 0, 11}, {k, 1, n+1}] // Flatten (* Jean-Fran├žois Alcover, Aug 13 2019 *)

CROSSREFS

Cf. A000110, A000296, A006505, A057837, A057814, A097147.

Row sums are A097147 for n >= 1.

Sequence in context: A285212 A262948 A193471 * A260615 A293298 A079134

Adjacent sequences:  A182928 A182929 A182930 * A182932 A182933 A182934

KEYWORD

nonn,tabl

AUTHOR

Peter Luschny, Apr 05 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 24 06:13 EST 2020. Contains 332199 sequences. (Running on oeis4.)