A097087 Exponents of 2 in the unreduced denominators of coefficients A097086(n)/2^a(n)*1/n! in function F(x) that satisfies F(F(x)) = x*exp(x).

0, 0, 0, 0, 1, 2, 3, 3, 3, 4, 4, 6, 6, 7, 8, 6, 7, 8, 7, 8, 9, 6, 12, 10, 12, 13, 13, 15, 15, 16, 17, 13, 15, 16, 14, 16, 17, 18, 19, 19, 19, 20, 21, 23, 23, 24, 25, 24, 24, 25, 22, 24, 26, 26, 29, 27, 29, 30, 30, 32, 32, 33, 34, 32, 31, 32, 31, 32

Offset

0,6

Comments

A097086 lists the unreduced numerators.

Links

Table of n, a(n) for n=0..67.

Formula

E.g.f.: F(x) = Sum_{n>=0} A097086(n)/2^a(n)*x^n/n! where F(F(x)) = x*exp(x).

Prog

(PARI) {a(n)=local(A, B, F=x*exp(x+x^2*O(x^n))); A=F; for(i=0, n, B=serreverse(A); A=(A+subst(B, x, F))/2); valuation(denominator(n!*polcoeff(A, n, x)), 2)}

Crossrefs

Cf. A097086.

Sequence in context: A181550 A134841 A071112 * A153161 A346373 A238516

Adjacent sequences: A097084 A097085 A097086 * A097088 A097089 A097090

Keyword

nonn

Author

Paul D. Hanna, Jul 23 2004

Status

approved