Number of self-inverse permutations in S_n with longest increasing subsequence of length 4.
A217324
Number of self-inverse permutations in S_n with longest increasing subsequence of length 4.
Terms
- a(0) =1a(1) =4a(2) =19a(3) =69a(4) =265a(5) =929a(6) =3356a(7) =11626a(8) =41117a(9) =142206a(10) =499836a(11) =1734328a(12) =6099193a(13) =21282265a(14) =75125770a(15) =263906332a(16) =936517637a(17) =3313246237a(18) =11827430209a(19) =42139231729a(20) =151339387003a(21) =542857007499
External references
- oeis: A217324