131901domain: NAppears in sequencesExpansion of 1/((1-6x)(1-7x)(1-8x)(1-10x)).at n=4A028201Solution of the complementary equation a(n) = a(n-1) + a(n-2) + 2*b(n-1) - b(n-2) - 2, where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4.at n=21A294426