83736

Appears in sequences

• Number of permutations of 3 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.at n=4A151632
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(3*n+1,i) * binomial(k+3-i,3)^n, 0 <= k <= 3*(n-1).at n=24A174266
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(3*n+1,i) * binomial(k+3-i,3)^n, 0 <= k <= 3*(n-1).at n=32A174266
• Number of 4 X n binary arrays without the pattern 0 1 diagonally, vertically, antidiagonally or horizontally.at n=38A188555
• G.f.: A(x) = INV(x - x*INV(x - 2*x*INV(x - 3*x*INV(x - 4*x*INV(x - ...))))), where INV(F(x)) = series reversion of F(x).at n=6A195194
• Number of endofunctions f on [2n] that are self-inverse on [n].at n=4A245141
• Number T(n,k) of endofunctions f on [n] that are self-inverse on [k]; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=40A245348
• Number A(n,k) of endofunctions f on [2n] satisfying f^k(i) = i for all i in [n]; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=25A246070
• Number of n-node rooted trees in which seven equals the maximal number of nodes in paths starting at a leaf and ending at the first branching node or at the root.at n=12A318903