A322095 - OEIS

%I #23 Nov 29 2018 06:26:01

%S 1,0,2,339720,549023310936,4383995385521886720,

%T 131828993822765959468851600,12202002913678756821228939869239920,

%U 2988325485815656468293009880545684170044800,1723427149081248135793318785599849462668815779427840

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

%H Seiichi Manyama, <a href="/A322095/b322095.txt">Table of n, a(n) for n = 0..80</a>

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

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

%Y Row 7 of A322093.

%Y Cf. A190836, A322127, A322128.

%K nonn

%O 0,3

%A _Seiichi Manyama_, Nov 28 2018