cp's OEIS Frontend

A213701 Half the number of 6X6 0..n symmetric arrays with no 2X2 subblock summing to 2n.

%I A213701 #6 Jul 22 2025 23:03:43
%S A213701 5148,168382284,193946752094,34389632236877,2256314178023600,
%T A213701 72037480156866493,1425762604012263360,19265705246048238885,
%U A213701 196522537519121864954,1582723194473524459497,10592676749133340851406
%N A213701 Half the number of 6X6 0..n symmetric arrays with no 2X2 subblock summing to 2n.
%C A213701 Row 5 of A213697
%H A213701 R. H. Hardin, <a href="/A213701/b213701.txt">Table of n, a(n) for n = 1..15</a>
%e A213701 Some solutions for n=4
%e A213701 ..4..4..4..3..4..3....0..3..2..2..1..2....4..2..4..2..2..1....0..3..2..1..3..4
%e A213701 ..4..0..1..1..2..3....3..3..4..1..0..4....2..3..1..0..1..0....3..4..4..4..2..1
%e A213701 ..4..1..3..4..2..3....2..4..4..1..2..4....4..1..1..0..4..4....2..4..4..1..0..1
%e A213701 ..3..1..4..0..1..4....2..1..1..3..3..3....2..0..0..4..3..4....1..4..1..1..0..4
%e A213701 ..4..2..2..1..3..3....1..0..2..3..0..4....2..1..4..3..1..1....3..2..0..0..0..3
%e A213701 ..3..3..3..4..3..0....2..4..4..3..4..4....1..0..4..4..1..0....4..1..1..4..3..1
%K A213701 nonn
%O A213701 1,1
%A A213701 _R. H. Hardin_ Jun 18 2012