Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k increasing cycles of length >=2 (0<=k<= n/2). 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) < ... .

A186757

Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k increasing cycles of length >=2 (0<=k<= n/2). 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) < ... .

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =4a(6) =10a(7) =11a(8) =3a(9) =59a(10) =36a(11) =25a(12) =363a(13) =212a(14) =130a(15) =15a(16) =2491a(17) =1688a(18) =651a(19) =210a(20) =19661a(21) =14317a(22) =4487a(23) =1750a(24) =105a(25) =176536a(26) =129076a(27) =42435a(28) =12628a(29) =2205

External references