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%I #26 Nov 08 2022 02:18:01
%S 1,1,2,6,24,120,720,4920,37488,319644,3033264,31784280,364902480,
%T 4538652840,61102571376,885045657564,13722397569072,226742901078120,
%U 3977354871110160,73816786920489720,1444940702597713008,29750236302549282948
%N Number of permutations p of 1,2,...,n satisfying p(i+6)-p(i)<>6 for all 1<=i<=n-6.
%C a(n) is also number of ways to place n nonattacking pieces rook + semi-leaper[6,6] on an n X n chessboard.
%H Vaclav Kotesovec, <a href="/A189285/b189285.txt">Table of n, a(n) for n = 0..24</a> (Updated Jan 19 2019)
%H Vaclav Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p. 644.
%H Vaclav Kotesovec, <a href="/A189285/a189285.txt">Mathematica program for this sequence</a>
%H George Spahn and Doron Zeilberger, <a href="https://arxiv.org/abs/2211.02550">Counting Permutations Where The Difference Between Entries Located r Places Apart Can never be s (For any given positive integers r and s)</a>, arXiv:2211.02550 [math.CO], 2022.
%F Asymptotics (V. Kotesovec, Mar 2011): a(n)/n! ~ (1 + 11/n + 30/n^2)/e.
%F Generally (for this sequence is d=6): 1/e*(1+(2d-1)/n+d*(d-1)/n^2).
%Y Cf. A000255, A189281, A189282, A189283, A189284, A189271.
%K nonn,hard
%O 0,3
%A _Vaclav Kotesovec_, Apr 19 2011
%E Terms a(23)-a(24) from _Vaclav Kotesovec_, Apr 21 2012