65752domain: NAppears in sequencesSolution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2) + n, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=18A294416a(n) = [x^n] Product_{k=1..n} ((1 + x^k)/(1 - x^k))^(n^k).at n=5A300456