271720

Appears in sequences

• a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-5) with a(1) = 1, a(2) = 2, a(3) = 4, a(4) = 8, and a(5) = 15.at n=20A385107