57611945197domain: NAppears in sequencesa(n) = 2*a(n-1) + a(n-2) + 1, a(0) = 1, a(1) = 2.at n=28A098790Nonnegative integers n such that 2n^2 + 2n - 3 is square.at n=28A124124a(n) = a(n-1) + 3*a(n-2) + a(n-3) with a(0) = 1, a(1) = 3, a(2) = 6.at n=28A375726