cp's OEIS Frontend

A211916 T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1.

%I A211916 #7 Jun 02 2025 07:52:08
%S A211916 0,0,1,0,1,6,0,0,10,25,0,0,10,214,70,0,0,10,802,1946,156,0,0,10,1492,
%T A211916 27963,10431,301,0,0,0,1732,227388,394117,40561,526,0,0,0,1744,
%U A211916 1085432,9345480,3243531,127275,855,0,0,0,1744,3104732,146208485,172044141
%N A211916 T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1.
%C A211916 Table starts
%C A211916 ...0......0........0..........0............0............0.............0
%C A211916 ...1......1........0..........0............0............0.............0
%C A211916 ...6.....10.......10.........10...........10............0.............0
%C A211916 ..25....214......802.......1492.........1732.........1744..........1744
%C A211916 ..70...1946....27963.....227388......1085432......3104732.......5535160
%C A211916 .156..10431...394117....9345480....146208485...1546571632...11174140231
%C A211916 .301..40561..3243531..172044141...6410611003.173414544149.3472263194283
%C A211916 .526.127275.18826250.1908272916.140836842878
%H A211916 R. H. Hardin, <a href="/A211916/b211916.txt">Table of n, a(n) for n = 1..85</a>
%e A211916 Some solutions for n=4 k=4
%e A211916 ..0........0........0........0........0........0........0........0
%e A211916 ..1.2......1.2......1.2......1.2......1.2......1.2......1.2......1.2
%e A211916 ..0.3.4....3.4.1....3.0.4....3.4.5....3.4.1....3.4.3....3.4.1....3.4.0
%e A211916 ..5.6.2.3..0.5.0.4..1.5.3.5..0.1.0.4..0.5.2.6..1.5.0.5..5.2.3.6..1.5.3.6
%K A211916 nonn,tabl
%O A211916 1,6
%A A211916 _R. H. Hardin_ Apr 25 2012