A322095 Number of permutations of 7 copies of 1..n with no element equal to another within a distance of 1.

1, 0, 2, 339720, 549023310936, 4383995385521886720, 131828993822765959468851600, 12202002913678756821228939869239920, 2988325485815656468293009880545684170044800, 1723427149081248135793318785599849462668815779427840

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..80

Formula

a(n) = n! * A190836(n).

a(n) = Integral_{0..infinity} (Sum_{k=1..7} (-1)^(7-k) * binomial(6, 7-k) * x^k/k!)^n * exp(-x) dx.

Crossrefs

Row 7 of A322093.

Cf. A190836, A322127, A322128.

Sequence in context: A151606 A176939 A070694 * A158346 A018854 A139181

Adjacent sequences: A322092 A322093 A322094 * A322096 A322097 A322098

Keyword

nonn

Author

Seiichi Manyama, Nov 28 2018

Status

approved