189695

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k nonincreasing odd cycles (0<=k<=floor(n/3)). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1)<b(2)<b(3)<... . A cycle is said to be odd if it has an odd number of entries. For example, the permutation (152)(347)(6)(8) has 1 nonincreasing odd cycle.at n=19A186766
• G.f. A(x) satisfies 1 - x = Sum_{n>=0} (-1)^(n mod 3) * x^n * A(x)^(n^2).at n=7A387475