OFFSET
0,3
COMMENTS
Analog of the inverse binomial transform of G_(n)^{(q)} with q=2, A135922.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..91
FORMULA
a(n) ~ c * 3^(n^2/4), where c = EllipticTheta[3,0,1/3]/QPochhammer[1/3,1/3] = 3.019783845699... if n is even and c = EllipticTheta[2,0,1/3]/QPochhammer[1/3,1/3] = 3.01826904637117... if n is odd. - Vaclav Kotesovec, Aug 23 2013
MAPLE
b:= proc(n) option remember; add(mul(
(3^(i+k)-1)/(3^i-1), i=1..n-k), k=0..n)
end:
a:= proc(n) option remember;
add(b(n-j)*binomial(n, j)*(-1)^j, j=0..n)
end:
seq(a(n), n=0..19); # Alois P. Heinz, Sep 24 2019
MATHEMATICA
Table[SeriesCoefficient[Sum[x^n/Product[(1-(3^k-1)*x), {k, 0, n}], {n, 0, nn}], {x, 0, nn}] , {nn, 0, 20}] (* Vaclav Kotesovec, Aug 23 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
R. J. Mathar, Aug 21 2013
STATUS
approved