|
| |
|
|
A001247
|
|
Squares of Bell numbers.
|
|
1
| |
|
|
1, 1, 4, 25, 225, 2704, 41209, 769129, 17139600, 447195609, 13450200625, 460457244900, 17754399678409, 764214897046969, 36442551140059684, 1912574337188517025, 109833379421325769609, 6866586647633870998416
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
FORMULA
| E.g.f.: exp(exp(x*(d_z) - 1))*(exp(exp(z)-1)) |_{z=0}, with the derivative operator d_z := d/dz. From eqs.(16) and (17) of the 1999 C. M. Bender reference given in A000110.
E.g.f.: exp(-2)*Sum(exp(exp(n*x))/n!,n=0..infinity). - Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 31 2008
|
|
|
MAPLE
| with (combinat):seq(mul(bell(n), k=1..2), n=0..17); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 21 2007
|
|
|
MATHEMATICA
| Table[BellB[n, 1]^2, {n, 0, 17}] [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 16 2009]
|
|
|
PROG
| (Other) sage: [(bell_number(n))^2 for n in xrange(0, 18)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 15 2009]
|
|
|
CROSSREFS
| Cf. A000110.
Sequence in context: A060911 A060912 A050386 * A031152 A010845 A087660
Adjacent sequences: A001244 A001245 A001246 * A001248 A001249 A001250
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| More terms from Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Sep 21 2007
|
| |
|
|
