cp's OEIS Frontend

A266126 Number of n X 3 integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself.

%I A266126 #6 Jan 01 2024 18:24:08
%S A266126 4,25,77,385,2099,9083,48188,249446,1166325,6288299,31791039,
%T A266126 153857132,834409385,4178055126,20594948568,111887135749,558869714981,
%U A266126 2784252991713,15113219048778,75548474928693,378923024757908
%N A266126 Number of n X 3 integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself.
%C A266126 Column 3 of A266131.
%H A266126 R. H. Hardin, <a href="/A266126/b266126.txt">Table of n, a(n) for n = 1..210</a>
%F A266126 Empirical: a(n) = a(n-1) +2*a(n-2) +205*a(n-3) -120*a(n-4) -258*a(n-5) -10662*a(n-6) -1620*a(n-7) +5336*a(n-8) +88936*a(n-9) +201296*a(n-10) +58144*a(n-11) +86672*a(n-12) -1097792*a(n-13) -831920*a(n-14) -2968704*a(n-15) -782336*a(n-16) -723152*a(n-17) +635968*a(n-18) +3427456*a(n-19) +337216*a(n-20) -204224*a(n-21) -289664*a(n-22) -453120*a(n-23) +20992*a(n-24) -1536*a(n-25) -12288*a(n-26) for n>27.
%e A266126 Some solutions for n=4
%e A266126 ..1..1..1....1..1..0....0..2..0....2..1..0....0..0..0....0..1..1....0..2..1
%e A266126 ..0..0..1....1..0..1....1..0..1....1..1..1....0..2..0....1..0..1....0..0..1
%e A266126 ..0..2..0....2..1..1....1..1..2....2..0..1....1..0..1....1..1..2....0..2..0
%e A266126 ..1..0..0....2..1..0....0..1..2....1..1..0....0..2..0....2..1..0....0..0..1
%Y A266126 Cf. A266131.
%K A266126 nonn
%O A266126 1,1
%A A266126 _R. H. Hardin_, Dec 21 2015