40776

Appears in sequences

• Triangle T(n,k) (n >= 1, 0 <= k <= floor((n-1)/2)) read by rows, where T(n,k) = (k+1)T(n-1,k) + (2n-4k)T(n-1,k-1).at n=27A101280
• G.f. A(x) satisfies A(x) = 1 + x*A(x*A(x)^3).at n=8A143501
• Number of ways to place 2 nonattacking zebras on an n X n board.at n=16A172137
• The number of the ordered triples (A,B,C) satisfying the system of the modular relations {A*B - B*A = C, B*C - C*B = A, C*A - A*C = B}, where A,B,C are distinct 2 X 2 matrices over Z(n).at n=34A194894
• Total number of inversions over all involutions of length n.at n=9A211606
• Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00010001.at n=8A260539
• Number of 4-sided prudent polygons of area n.at n=10A348925
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A143501.at n=53A384581