cp's OEIS Frontend

A365468 Number of n X n nonnegative integer arrays with upper left entry 0, lower right entry n - 5, every value within 4 of its king-move distance from the upper left, and every value increasing by 0 or 1 with every step right, diagonally southeast, or down.

%I A365468 #17 Sep 05 2023 16:56:30
%S A365468 0,0,0,0,1,251,35176,4105312,466029138,54944041476,6886218018445,
%T A365468 920364154307990,130498580283240363,19482086451147555715,
%U A365468 3039784702880850466554,492560752706827973431360,82451674043232981553367317,14196926753609833253834234271
%N A365468 Number of n X n nonnegative integer arrays with upper left entry 0, lower right entry n - 5, every value within 4 of its king-move distance from the upper left, and every value increasing by 0 or 1 with every step right, diagonally southeast, or down.
%H A365468 Robert Dougherty-Bliss and Manuel Kauers, <a href="https://arxiv.org/abs/2309.00487">Hardinian Arrays</a>, arXiv 2309.00487 [math.CO], 2023.
%F A365468 Conjecture: a(n) ~ (2^2 / (3^16 * Pi^2)) * 256^n / n^6.
%e A365468 Example for n = 7:
%e A365468   0011112
%e A365468   0111222
%e A365468   0111222
%e A365468   0112222
%e A365468   0112222
%e A365468   1111222
%e A365468   2222222
%Y A365468 Cf. A253026, A253217, A252998.
%K A365468 nonn
%O A365468 1,6
%A A365468 _Robert Dougherty-Bliss_, Sep 04 2023