cp's OEIS Frontend

A208467 Number of 2Xn nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

%I A208467 #7 Jul 22 2025 21:22:53
%S A208467 2,15,198,4041,113458,4132120,187612143,10318694804,672619407731,
%T A208467 51074630353994,4455159144290726,441285917587055633,
%U A208467 49152543937083199076,6105599904286957450405,839738743273230043872218
%N A208467 Number of 2Xn nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.
%C A208467 Row 2 of A208466
%H A208467 R. H. Hardin, <a href="/A208467/b208467.txt">Table of n, a(n) for n = 1..34</a>
%e A208467 Some solutions for n=4
%e A208467 ..0..0..1..0....0..1..1..0....0..0..1..0....0..0..0..0....0..0..0..0
%e A208467 ..0..1..0..0....0..0..0..1....0..0..2..0....1..1..2..0....0..1..0..2
%K A208467 nonn
%O A208467 1,1
%A A208467 _R. H. Hardin_ Feb 27 2012