-1281

Appears in sequences

• Coefficients of period polynomials.at n=16A006309
• Let c(n) = x^(2^n-1)*(1-x^(2^n)), g(n) = 1 + x^(2^n-1) + x^(2^n), h(n) = Product_{i=1..n} g(i); then use g.f. (1+2*x) - Sum_{n>=1} c(n)/h(n).at n=66A151684
• Expansion of Product_{k>0} (1 - d(k)*x^k), where d(k) is the number of divisors of k.at n=50A321619