Number of permutations of {1,2,...,n} having no increasing odd cycles. 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.
A186762
Number of permutations of {1,2,...,n} having no increasing odd cycles. 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.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =1a(4) =9a(5) =33a(6) =235a(7) =1517a(8) =12593a(9) =111465a(10) =1122819a(11) =12313409a(12) =147949593a(13) =1922353925a(14) =26918452691a(15) =403744456541
External references
- oeis: A186762