OFFSET
0,2
FORMULA
a(n) ~ c * 2^(n*(n+1)/2), where c = Product_{k>=1} (1 + k/2^k) = 5.52995584900...
MATHEMATICA
Table[Product[2^k+k, {k, 1, n}], {n, 0, 15}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 10 2016
STATUS
approved