# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a297954 Showing 1-1 of 1 %I A297954 #7 Mar 22 2018 12:54:38 %S A297954 1,7,15,25,47,109,245,545,1253,2859,6557,15131,34879,80643,186663, %T A297954 432253,1002043,2323805,5391149,12511905,29043489,67430735,156577101, %U A297954 363614071,844480819,1961394067,4555748943,10582066605,24580613559,57098398457 %N A297954 Number of n X 3 0..1 arrays with every element equal to 1, 2, 4 or 5 king-move adjacent elements, with upper left element zero. %C A297954 Column 3 of A297959. %H A297954 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A297954 Empirical: a(n) = 2*a(n-1) + 2*a(n-2) + a(n-3) - 8*a(n-4) - 2*a(n-5) - 2*a(n-6) + 2*a(n-7) - a(n-8) + 2*a(n-9) + 3*a(n-11) + 2*a(n-12) for n>13. %F A297954 Empirical g.f.: x*(1 - 2*x)*(1 + 7*x + 13*x^2 + 6*x^3 - 20*x^4 - 32*x^5 - 20*x^6 - 8*x^7 - 9*x^8 - 9*x^9 - 7*x^10 - 2*x^11) / ((1 - x)*(1 - x - 3*x^2 - 4*x^3 + 4*x^4 + 6*x^5 + 8*x^6 + 6*x^7 + 7*x^8 + 5*x^9 + 5*x^10+ 2*x^11)). - _Colin Barker_, Mar 22 2018 %e A297954 Some solutions for n=7: %e A297954 ..0..0..1. .0..1..0. .0..1..1. .0..1..1. .0..0..1. .0..1..1. .0..1..0 %e A297954 ..1..1..1. .1..0..0. .0..1..0. .0..0..1. .1..0..1. .0..1..0. .1..0..1 %e A297954 ..1..0..0. .1..0..0. .1..1..0. .1..1..1. .0..1..0. .1..0..1. .0..1..0 %e A297954 ..1..1..0. .0..1..0. .1..1..1. .0..1..1. .0..1..1. .0..0..1. .0..1..1 %e A297954 ..1..1..1. .1..0..0. .1..0..0. .0..1..0. .0..1..1. .0..0..1. .0..1..1 %e A297954 ..1..0..0. .1..0..0. .1..1..1. .1..0..1. .0..1..0. .1..0..0. .0..1..0 %e A297954 ..1..1..0. .0..1..0. .0..0..1. .0..1..0. .1..1..0. .0..1..1. .1..1..0 %Y A297954 Cf. A297959. %K A297954 nonn %O A297954 1,2 %A A297954 _R. H. Hardin_, Jan 09 2018 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE