58926domain: NAppears in sequencesa(n) = pg(3, n) + pg(4, n) + ... + pg(n, n) where pg(m, n) is the n-th m-th-order polygonal number.at n=23A241452G.f.: Sum_{k>=1} x^(2*k)/(1+x^(2*k)) * Product_{k>=1} 1/(1-x^k).at n=40A305121The five digits of a(n) and their four successive absolute first differences are all distinct.at n=33A365257