OFFSET
0,2
FORMULA
MATHEMATICA
nmax = 56; CoefficientList[Series[Product[(1 + x^(2^k) + x^(2^(k + 1)))^2, {k, 0, Floor[Log[2, nmax]] + 1}], {x, 0, nmax}], x]
nmax = 56; A[_] = 1; Do[A[x_] = (1 + x + x^2)^2 A[x^2] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jul 09 2019
STATUS
approved