86880

Appears in sequences

• Number of 6-step left-handed knight's tours (moves only out two, left one) on an n X n board summed over all starting positions.at n=22A187176
• Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock diagonal minimum minus antidiagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal maximum nondecreasing vertically.at n=9A253229
• G.f. A(x) satisfies: 1 = ...((((A(x) - 2*x)^2 - 4*x^2)^2 - 8*x^3)^2 - 16*x^4)^2 -... - 2^n*x^n)^2 -...., a series of infinite nested squares.at n=26A274850