The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #5 Dec 18 2015 18:17:45
%S 1,81,39609,119743353,2266745635377,270149651796118149,
%T 203368493873412168605037,969036564714736790447759054277
%N Number of lower triangles of an n X n integer array with each element differing from all of its vertical and horizontal neighbors by 4 or less and triangles differing by a constant counted only once
%C Column 4 of A195278
%e Some solutions for n=5
%e ...0...............0...............0...............0...............0
%e ...1..4............1..1............1..0............2..5...........-3.-1
%e ..-1..3..2.........4..3..7.........3..0..4.........1..2..6........-6.-5.-9
%e ..-4.-1..3..7......3..6.10..7......1..2..0.-3......0..0..2..4.....-6.-7.-8-10
%e ...0.-3..0..4..2...4..4..8..9..6...0..3..2..1..4..-4.-4.-1..2..2.-10-10.-8-11-13
%K nonn
%O 1,2
%A _R. H. Hardin_ Sep 14 2011