cp's OEIS Frontend

A195213 Number of lower triangles of an n X n integer array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by 1 or less and triangles differing by a constant counted only once.

%I A195213 #9 Jul 22 2025 12:40:05
%S A195213 1,7,91,2277,111031,10654607,2021888119,761408842173,570411420721871,
%T A195213 851650667866314005,2537743716708476573853,15108768742290768272235707,
%U A195213 179885152873727967922701202921,4286156683596201247493358770260469
%N A195213 Number of lower triangles of an n X n integer array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by 1 or less and triangles differing by a constant counted only once.
%C A195213 Column 1 of A195220
%H A195213 R. H. Hardin, <a href="/A195213/b195213.txt">Table of n, a(n) for n = 1..16</a>
%e A195213 Some solutions for n=5
%e A195213 ...0...............0...............0...............0...............0
%e A195213 ...1..0...........-1.-1...........-1..0...........-1..0............1..1
%e A195213 ...0..0..1........-2.-2.-1........-1..0..1.........0..0.-1.........0..1..0
%e A195213 ...0..1..1..1.....-1.-1.-1.-2......0..0..0..1......1..0.-1.-2......0..1..1..0
%e A195213 ...1..0..1..0..0..-1.-1.-2.-1.-2...0..0..1..1..2...1..0.-1.-2.-1...0..0..1..1..0
%K A195213 nonn
%O A195213 1,2
%A A195213 _R. H. Hardin_ Sep 13 2011