A076903 - OEIS

%I #33 Aug 21 2018 05:56:01

%S 1,1,1,5,5,13,203,877,23,1007,4639,22619,4213597,27644437,95449661,

%T 276591709,10480142147,255755771,97439543737,5832742205057,

%U 263898766507,158289938718917,88366975263673,22076002927542173,148652956431601763,356814640940769181

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

%H Alois P. Heinz, <a href="/A076903/b076903.txt">Table of n, a(n) for n = 0..577</a> (first 151 terms from Muniru A Asiru)

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

%e 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, ...

%p seq(numer(coeff(series(exp(exp(x)-1), x,n+1),x,n)),n=0..25); # _Muniru A Asiru_, Aug 02 2018

%t a[x_] := BellB[x]/GCD[BellB[x], x!]; Array[a, 30, 0] (* _Alex Meiburg_, Jan 29 2011 *)

%t Numerator[CoefficientList[Series[Exp[Exp[x]-1],{x,0,30}],x]] (* _Harvey P. Dale_, Oct 08 2013 *)

%o (PARI) x= 'x + O('x^50); apply(x->numerator(x), Vec((exp(exp(x)-1)))) \\ _Michel Marcus_, Aug 04 2018

%o (GAP) List([0..25],n->Bell(n)/Gcd(Bell(n),Factorial(n))); # _Muniru A Asiru_, Aug 20 2018

%Y Cf. A000110, A000142, A076904 (denominators).

%K frac,nonn

%O 0,4

%A _Benoit Cloitre_, Nov 27 2002