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 A275063 Number of permutations p of [n] such that p(i)-i is a multiple of eight for all i in [n]. 2

%I

%S 1,1,1,1,1,1,1,1,1,2,4,8,16,32,64,128,256,768,2304,6912,20736,62208,

%T 186624,559872,1679616,6718464,26873856,107495424,429981696,

%U 1719926784,6879707136,27518828544,110075314176,550376570880,2751882854400,13759414272000

%N Number of permutations p of [n] such that p(i)-i is a multiple of eight for all i in [n].

%H Alois P. Heinz, <a href="/A275063/b275063.txt">Table of n, a(n) for n = 0..665</a>

%F a(n) = Product_{i=0..7} floor((n+i)/8)!.

%F a(n) ~ (2*Pi*n)^(7/2) * n! / 8^(n + 4). - _Vaclav Kotesovec_, Oct 02 2018

%e a(9) = 2: 123456789, 923456781.

%t Table[Product[Floor[(n + i)/8]!, {i, 0, 7}], {n, 0, 40}] (* _Vaclav Kotesovec_, Oct 02 2018 *)

%Y Column k=8 of A275062.

%K nonn

%O 0,10

%A _Alois P. Heinz_, Jul 15 2016

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Last modified June 16 18:25 EDT 2021. Contains 345066 sequences. (Running on oeis4.)