-2121

Appears in sequences

• Expansion of psi(q^3) / psi(q)^3 in powers of q where psi() is a Ramanujan theta function.at n=13A132979
• Expansion of q^(-1) * psi(-q) / psi(-q^3)^3 in powers of q where psi() is a Ramanujan theta function.at n=40A133637
• Expansion of q^(-1) * psi(q) / psi(q^3)^3 in powers of q where psi() is a Ramanujan theta function.at n=40A258093
• Alternating sum of heptagonal numbers.at n=41A266085
• Product_{n>=1} (1 + x^n)^a(n) = 1 + Sum_{n>=1} phi(n) * x^n, where phi = A000010.at n=23A328774