A263690 Number of length n arrays of permutations of 0..n-1 with each element moved by -n to n places and every three consecutive elements having its maximum within 3 of its minimum.
1, 1, 2, 6, 24, 36, 36, 48, 80, 128, 200, 288, 432, 648, 992, 1496, 2272, 3424, 5192, 7840, 11880, 17952, 27184, 41096, 62208, 94072, 142368, 215328, 325832, 492864, 745736, 1128096, 1706800, 2582024, 3906464, 5909784, 8941024, 13526368, 20464072, 30959200
Offset: 0
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..5558
Formula
Empirical: a(n) = a(n-1) +a(n-2) -a(n-3) +a(n-4) for n>12.
G.f.: (8*x^12+8*x^11-4*x^10-8*x^8+6*x^7+20*x^6-7*x^5-16*x^4-4*x^3-1) / (x^4-x^3+x^2+x-1). - Alois P. Heinz, Apr 08 2020
Extensions
a(0), a(24)-a(39) from Alois P. Heinz, Apr 08 2020