Number of permutations of 1..n with the difference of the k-th adjacent pair no greater than k, k=1..n-1.
A179981
Number of permutations of 1..n with the difference of the k-th adjacent pair no greater than k, k=1..n-1.
Terms
- a(0) =2a(1) =4a(2) =10a(3) =26a(4) =82a(5) =294a(6) =1210a(7) =5642a(8) =29658a(9) =171302a(10) =1082098a(11) =7427510a(12) =54982606a(13) =436014046a(14) =3689906314a(15) =33184698742a(16) =316299334442
External references
- oeis: A179981