cp's OEIS Frontend

A222460 Number of n X 4 0..7 arrays with no entry increasing mod 8 by 7 rightwards or downwards, starting with upper left zero.

%I A222460 #7 Mar 15 2018 10:12:17
%S A222460 343,556549,903055069,1465295106499,2377584520856755,
%T A222460 3857863258420747009,6259760185235726701945,
%U A222460 10157072698503130798653535,16480843155302567299412163919,26741778775464749134872807556861
%N A222460 Number of n X 4 0..7 arrays with no entry increasing mod 8 by 7 rightwards or downwards, starting with upper left zero.
%C A222460 Column 4 of A222462.
%H A222460 R. H. Hardin, <a href="/A222460/b222460.txt">Table of n, a(n) for n = 1..210</a>
%F A222460 Empirical: a(n) = 1689*a(n-1) - 108775*a(n-2) + 1672631*a(n-3).
%F A222460 Empirical g.f.: 7*x*(49 - 3254*x + 50519*x^2) / (1 - 1689*x + 108775*x^2 - 1672631*x^3). - _Colin Barker_, Mar 15 2018
%e A222460 Some solutions for n=3:
%e A222460 ..0..4..2..3....0..0..6..3....0..2..0..1....0..0..2..0....0..4..4..6
%e A222460 ..0..0..4..1....0..0..4..1....0..0..2..5....0..0..3..4....0..0..1..7
%e A222460 ..0..0..4..6....0..0..6..3....0..0..4..2....0..0..6..2....0..0..3..7
%Y A222460 Cf. A222462.
%K A222460 nonn
%O A222460 1,1
%A A222460 _R. H. Hardin_, Feb 21 2013