cp's OEIS Frontend

A219078 T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 nXk array.

%I A219078 #6 Jul 23 2025 00:13:00
%S A219078 1,3,1,5,11,1,9,47,41,1,17,165,337,149,1,31,625,2321,2469,547,1,57,
%T A219078 2435,17537,32945,18499,2007,1,105,9367,134809,494713,477309,137251,
%U A219078 7361,1,193,35901,1023441,7561349,14228041,6879341,1019123,27001,1,355,137865
%N A219078 T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal, diagonal or antidiagonal neighbor in a random 0..1 nXk array.
%C A219078 Table starts
%C A219078 .1.......3...........5..............9.................17....................31
%C A219078 .1......11..........47............165................625..................2435
%C A219078 .1......41.........337...........2321..............17537................134809
%C A219078 .1.....149........2469..........32945.............494713...............7561349
%C A219078 .1.....547.......18499.........477309...........14228041.............433704331
%C A219078 .1....2007......137251........6879341..........407374825...........24734141495
%C A219078 .1....7361.....1019123.......99118753........11660290321.........1410242020653
%C A219078 .1...27001.....7573641.....1428782305.......333882416305........80444813963129
%C A219078 .1...99043....56263253....20594013941......9559854123673......4588436794733591
%C A219078 .1..363299...417979331...296830835781....273717397488937....261712432286491659
%C A219078 .1.1332617..3105269893..4278398369137...7837125931615553..14927540586501299193
%C A219078 .1.4888173.23069495037.61667023808785.224393896465841065.851435525780779197693
%H A219078 R. H. Hardin, <a href="/A219078/b219078.txt">Table of n, a(n) for n = 1..197</a>
%e A219078 Some solutions for n=3 k=4
%e A219078 ..1..1..0..0....1..1..1..1....1..0..0..1....1..1..1..1....0..0..1..1
%e A219078 ..0..0..1..0....1..0..0..1....1..1..0..0....1..1..1..0....1..1..1..0
%e A219078 ..0..1..0..0....1..1..0..1....1..0..1..1....0..1..0..1....0..0..0..1
%Y A219078 Column 2 is A218348
%Y A219078 Row 1 is A000213(n+1)
%K A219078 nonn,tabl
%O A219078 1,2
%A A219078 _R. H. Hardin_ Nov 11 2012