575270

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k up-down cycles (0<=k<=n). A cycle (b(1), b(2), ...) is said to be up-down if, when written with its smallest element in the first position, it satisfies b(1)<b(2)>b(3)<... .at n=55A186358
• Number of permutations of {1,2,...,n} having no up-down cycles. A cycle (b(1), b(2), ...) is said to be up-down if, when written with its smallest element in the first position, it satisfies b(1)<b(2)>b(3)<... .at n=10A186359
• Number of 2*n X 8 binary arrays with row sums 4 and column sums n, avoiding the patterns 010 and 101 in any row and column.at n=5A381554