100580domain: NAppears in sequencesa(n) is the sum of products of terms in all partitions of n.at n=19A006906Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2) + 3, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=19A294555