Number of permutations of {1..n} with the sum of squared adjacent differences <= n*(n+1)/2.
A180070
Number of permutations of {1..n} with the sum of squared adjacent differences <= n*(n+1)/2.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =12a(5) =44a(6) =116a(7) =374a(8) =1428a(9) =5960a(10) =26016a(11) =120570a(12) =590598a(13) =3065372a(14) =16566508a(15) =92827128a(16) =542485764a(17) =3298228302a(18) =20696614200a(19) =133722820270a(20) =892046755174
External references
- oeis: A180070