OFFSET
1,1
FORMULA
a(n)=2^((1/6)*n*(n+1)*(n+2))*product(product(2^p-1, p = 1..l), l = 1..n-1).
a(n) ~ c * QPochhammer(1/2)^n * 2^(n*(2*n^2 + 3*n + 1)/6), where c = 10.032129775337715051413862095841451215826928327290198829... - Vaclav Kotesovec, Apr 17 2018
MAPLE
a(n) := 2^((1/6)*n*(n+1)*(n+2))*mul(mul(2^p-1, p = 1..l), l = 1..n-1):
MATHEMATICA
Table[2^(n*(n+1)*(n+2)/6) * Product[Product[2^p-1, {p, 1, m}], {m, 1, n-1}], {n, 1, 10}] (* Vaclav Kotesovec, Apr 17 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
P. Dunin-Barkowski, A. Sleptsov (elandread(AT)yandex.ru), Mar 20 2009
STATUS
approved