OFFSET
0,4
COMMENTS
The above function t2 simplifies to t2(z) = 1 + z^2 + z^6 + z^12 + ... = sum_{n>=0} z^(n(n+1)) = sum_{n>=0} z^A002378(n). But the sequence lists only the coefficients of even powers, i.e., with t2 replaced by t(z) = 1 + z + z^3 + z^6 + ..., cf. formula. - M. F. Hasler, Oct 17 2014
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
FORMULA
Coefficients of product_{d|33} t(x^d), with t(z) = sum_{n>=0} z^(n(n+1)/2) = sum_{n>=0} z^A000217(n). - M. F. Hasler, Oct 17 2014
PROG
(PARI) my(x='x+O('x^99), t(z)=sum(i=0, 10, z^((i+1)*i/2))); Vec(prod(i=1, #d=divisors(33), t(x^d[i]))) \\ M. F. Hasler, Oct 17 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Seiichi Manyama, May 24 2017
STATUS
approved