A076903 Numerator of coefficients of power series for exp(exp(x)-1).

1, 1, 1, 5, 5, 13, 203, 877, 23, 1007, 4639, 22619, 4213597, 27644437, 95449661, 276591709, 10480142147, 255755771, 97439543737, 5832742205057, 263898766507, 158289938718917, 88366975263673, 22076002927542173, 148652956431601763, 356814640940769181

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..577 (first 151 terms from Muniru A Asiru)

Formula

a(n) = A000110(n) / gcd(A000110(n),n!).

Example

A076903 / A076904 = 1/1, 1/1, 1/1, 5/6, 5/8, 13/30, 203/720, 877/5040, 23/224, 1007/17280, 4639/145152, 22619/1330560, 4213597/479001600, ...

Maple

seq(numer(coeff(series(exp(exp(x)-1), x, n+1), x, n)), n=0..25); # Muniru A Asiru, Aug 02 2018

Mathematica

a[x_] := BellB[x]/GCD[BellB[x], x!]; Array[a, 30, 0] (* Alex Meiburg, Jan 29 2011 *)
Numerator[CoefficientList[Series[Exp[Exp[x]-1], {x, 0, 30}], x]] (* Harvey P. Dale, Oct 08 2013 *)

Prog

(PARI) x= 'x + O('x^50); apply(x->numerator(x), Vec((exp(exp(x)-1)))) \\ Michel Marcus, Aug 04 2018
(GAP) List([0..25], n->Bell(n)/Gcd(Bell(n), Factorial(n))); # Muniru A Asiru, Aug 20 2018

Crossrefs

Cf. A000110, A000142, A076904 (denominators).

Sequence in context: A171663 A126439 A318541 * A192987 A252768 A062367

Adjacent sequences: A076900 A076901 A076902 * A076904 A076905 A076906

Keyword

frac,nonn

Author

Benoit Cloitre, Nov 27 2002

Status

approved