Number of permutations of length n with two 4-sequences.
A247109
Number of permutations of length n with two 4-sequences.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =2a(6) =11a(7) =65a(8) =433a(9) =3271a(10) =27741a(11) =261231a(12) =2708064a(13) =30671367a(14) =377034018a(15) =5001404982a(16) =71229862678
External references
- oeis: A247109