A322308 Number of permutations sigma such that |sigma(i+j)-sigma(i)| >= 5 for 1 <= i <= n - j, 1 <= j <= 4.

1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 128, 6320, 344872

Offset: 0

Author

Seiichi Manyama, Dec 03 2018

Keywords

• nonn
• more

Comments

2 | a(n) for n > 1.

Examples

			a(25) = 2: [5,10,15,20,25,4,9,14,19,24,3,8,13,18,23,2,7,12,17,22,1,6,11,16,21] and its reverse.
		

Crossrefs

Cf. A179958, A279214, A322281.