# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a280476 Showing 1-1 of 1 %I A280476 #6 Sep 04 2022 08:10:16 %S A280476 6,63,997,15104,214635,2886700,37224679,464804972,5658641517, %T A280476 67497024458,791686330307,9155901061480,104627294693465, %U A280476 1183339450854998,13264070830389055,147510583604457748,1629077899911720149 %N A280476 Number of n X 4 0..2 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. %C A280476 Column 4 of A280480. %H A280476 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A280476 Empirical: a(n) = 51*a(n-1) -1155*a(n-2) +15629*a(n-3) -144180*a(n-4) +980916*a(n-5) -5175036*a(n-6) +21885648*a(n-7) -75880896*a(n-8) +219014768*a(n-9) -531595200*a(n-10) +1091740992*a(n-11) -1902278464*a(n-12) +2810785536*a(n-13) -3508065024*a(n-14) +3668507648*a(n-15) -3171179520*a(n-16) +2217664512*a(n-17) -1211863040*a(n-18) +487784448*a(n-19) -128974848*a(n-20) +16777216*a(n-21) for n>22. %e A280476 Some solutions for n=4 %e A280476 ..0..0..0..1. .0..0..1..1. .0..0..0..1. .0..1..1..1. .0..1..0..0 %e A280476 ..0..0..1..0. .0..0..0..2. .0..0..1..1. .1..1..1..0. .0..0..2..2 %e A280476 ..2..2..0..1. .1..1..2..2. .2..0..0..2. .1..2..0..0. .0..2..2..0 %e A280476 ..2..0..1..1. .1..2..2..2. .0..0..0..0. .2..2..2..2. .0..0..0..0 %Y A280476 Cf. A280480. %K A280476 nonn %O A280476 1,1 %A A280476 _R. H. Hardin_, Jan 04 2017 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE