OFFSET
0,3
FORMULA
E.g.f.: (exp(x^2)*(x+1) -1)/x. - Sergei N. Gladkovskii, Oct 10 2012
Sum_{n>=0} 1/a(n) = 3/2 + 5*exp(1/4)*sqrt(Pi)*erf(1/2)/4, where erf is the error function. - Amiram Eldar, Feb 13 2023
MATHEMATICA
Table[n!/Ceiling[n/2]!, {n, 0, 24}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 01 2012
EXTENSIONS
a(0)=1 prepended and e.g.f. edited by Alois P. Heinz, Sep 08 2015
STATUS
approved