Number of entries in the second cycles of all permutations of {1,2,...,n}; each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.
A138772
Number of entries in the second cycles of all permutations of {1,2,...,n}; each cycle is written with the smallest element first and cycles are arranged in increasing order of their first elements.
Terms
- a(0) =0a(1) =1a(2) =5a(3) =27a(4) =168a(5) =1200a(6) =9720a(7) =88200a(8) =887040a(9) =9797760a(10) =117936000a(11) =1536796800a(12) =21555072000a(13) =323805081600
External references
- oeis: A138772