1795236domain: NAppears in sequencesExpansion of Product_{k>=1} (1+x^k)^(2*k-1) / (1-x^k)^(2*k).at n=15A261384a(n) = 3*a(n-1) - 3*a(n-2) + 2*a(n-3) - 2*a(n-4) + a(n-5) for n >= 10, a(0) = 2, a(1) = 4, a(2) = 7, a(3) = 12, a(4) = 20, a(5) = 32, a(6) = 50, a(7) = 77, a(8) = 116, a(9) = 174.at n=33A289115