OFFSET
0,4
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
FORMULA
2^a(n) is denominator of c(n) where c(n) = (c(n-2) - (4*n-6)*c(n-1))/4, c(0) = 1, c(1) = 1/2. - Robert Israel, Nov 30 2023
MAPLE
S:= series(exp(-1+sqrt(1+x)), x, 201):
seq(padic:-ordp(denom(n!*coeff(S, x, n)), 2), n=0..200); # Robert Israel, Nov 30 2023
MATHEMATICA
IntegerExponent[Denominator[With[{nn=80}, CoefficientList[ Series[ Exp[ -1+Sqrt[1+x]], {x, 0, nn}], x] Range[0, nn]!]], 2] (* Harvey P. Dale, Aug 04 2021 *)
PROG
(PARI) my(x='x+O('x^30)); apply(x->(valuation(denominator(x), 2)), Vec(serlaplace(exp(sqrt(1+x)-1)))) \\ Michel Marcus, Nov 30 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Ralf Stephan, Dec 13 2004
EXTENSIONS
Definition clarified by Harvey P. Dale, Aug 04 2021
STATUS
approved