-2010

Appears in sequences

• Expansion of psi(x)^2 * phi(-x)^6 in powers of x where phi(), psi() are Ramanujan theta functions.at n=37A227695
• G.f.: 1/(1 + x/(1 + x^3/(1 + x^6/(1 + x^10/(1 + x^15/(1 + ... + x^(k*(k+1)/2)/(1 + ...))))))), a continued fraction.at n=23A285484
• Expansion of Product_{k>0} theta_3(q^(2*k))/theta_3(q^(2*k-1)), where theta_3() is the Jacobi theta function.at n=11A321027
• a(n) = n - 2^(sum of digits of n).at n=38A328882
• a(1)=0; thereafter a(n) = (n-1)*sigma(n)-n*sigma(n-1) where sigma is the sum-of-divisors function A000203.at n=40A335153