20679088

Appears in sequences

• a(n) = 2*a(n-1) + a(n-2) - 1, with a(0) = 0 and a(1) = 2.at n=20A353580
• a(n) = (A077446(n) + 1)/2 for n >= 0.at n=20A364319
• a(n) = a(n-1) + 3*a(n-2) + a(n-3) with a(0) = 1, a(1) = 3, a(2) = 6.at n=19A375726