OFFSET
0,2
FORMULA
a(n) ~ c * 2^n * n!, where c = Product_{k>=2} 1/(1 - 2^(1-k)/k!) = 1.39938283723373672673056837661175942499559257652969647531100283042201554... - Vaclav Kotesovec, Mar 28 2024
MATHEMATICA
nmax = 20; CoefficientList[Series[Product[1/(1 - 2 x^k/k!), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 27 2024
STATUS
approved