1815726domain: NAppears in sequencesa(n) = (4*n+1)*(4*n+2)*(4*n+3).at n=30A001505a(n) = (5*n + 1)*(5*n + 2)*(5*n + 3).at n=24A001509a(n) = binomial(5*n+8, 4)/5 for n >= 0.at n=23A238473