90921

Appears in sequences

• Coefficients of a Bessel function (reciprocal of J_0(z)); also pairs of permutations with rise/rise forbidden.at n=6A000275
• Matrix inverse of A008459 (squares of entries of Pascal's triangle).at n=21A055133
• The number of pairs of permutations in the product group S_n X S_n with k common descents, n >= 1 and 0 <= k <= n-1.at n=15A192721
• Number of n X 6 arrays with rows being permutations of 0..5 and no column j greater than column j-1 in all rows.at n=1A212853
• T(n,k) = number of n X k arrays with rows being permutations of 0..k-1 and no column j greater than column j-1 in all rows (n, k >= 1).at n=22A212855
• Number of permutations of length n that avoid the patterns 4123, 4231, and 4312.at n=10A257562
• Triangle read by rows, (Sum_{k=0..n} T[n,k]*x^k) / (1-x)^(n+1) are generating functions of the columns of A287316.at n=27A287315
• Square array read by descending antidiagonals. T(n,k) is the number of ways to separate the columns of an ordered pair of n-permutations (that have been written as a 2 X n array, one atop the other) into k cells so that no cell has a column rise. For n >= 0, k >= 0.at n=34A340986