15568077235domain: NAppears in sequencesNumber of solutions to k_1 + 2*k_2 + ... + n*k_n = 0, where k_i are from {-1,0,1}, i=1..n.at n=26A007576Largest coefficient in expansion of Product_{i=1..n} (1 + q^i + q^(2i)).at n=25A039826