31664

Appears in sequences

• 2n*binomial(2n,n) - 4^n.at n=7A068552
• Number of ways to place 2 nonattacking kings on an n X n cylindrical chessboard.at n=15A194650
• Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=9A207112
• 10-step Fibonacci sequence starting with 0,0,0,0,1,0,0,0,0,0.at n=25A251763
• Numbers k such that s(k) = s(k+1) but phi(k) != phi(k+1), where s(k) = phi(k) + phi(phi(k)) + ... + 1 is the sum of iterated phi (A092693).at n=16A291177