486680

Appears in sequences

• a(n) = n*(3*n^4 + 15*n^3 + 25*n^2 - 15*n - 28)/60.at n=24A365373
• G.f.: Sum_{k>=0} x^(k*(k+1)/2) * Product_{j=1..k} ((1 + x^j)/(1 - x^j))^2.at n=31A376853