cp's OEIS Frontend

A252931 Number of n X n nonnegative integer arrays with upper left 0 and every value within 3 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.

%I A252931 #8 Jul 23 2025 13:46:37
%S A252931 1,5,44,711,17962,578342,21312696,857248091,36723156004,1650365159314,
%T A252931 77015673357558,3704833216794534,182732875391479366,
%U A252931 9203662331845611018,471886132793225715184,24568007717042452684419,1296265434331412271116602
%N A252931 Number of n X n nonnegative integer arrays with upper left 0 and every value within 3 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.
%C A252931 Diagonal of A252938
%H A252931 R. H. Hardin, <a href="/A252931/b252931.txt">Table of n, a(n) for n = 1..24</a>
%e A252931 Some solutions for n=4
%e A252931 ..0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1
%e A252931 ..1..1..1..1....0..1..1..2....0..0..1..2....1..1..1..2....1..1..1..2
%e A252931 ..1..1..1..1....0..1..2..2....0..1..1..2....2..2..2..2....2..2..2..2
%e A252931 ..2..2..2..2....1..1..2..3....0..1..2..2....2..2..2..2....2..2..2..3
%K A252931 nonn
%O A252931 1,2
%A A252931 _R. H. Hardin_, Dec 24 2014