89478460

Appears in sequences

• a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + 2*a(n-4), where a(0) = 2, a(1) = 4, a(2) = 8, a(3) = 18.at n=25A288206
• a(n) = 1 - n + (2^(n+2) - (-1)^n)/3.at n=26A322783