# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a256022 Showing 1-1 of 1 %I A256022 #8 Dec 20 2018 10:16:59 %S A256022 33,68,154,352,798,1804,4086,9304,21194,48176,109506,249120,566754, %T A256022 1289056,2931842,6668688,15168650,34502104,78476674,178499728, %U A256022 406009530,923494792,2100545026,4777818256,10867446266,24718685528,56224184050 %N A256022 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 or 1 and no antidiagonal sum 0 or 1 and no row sum 1 and no column sum 1. %H A256022 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A256022 Empirical: a(n) = 2*a(n-1) -a(n-2) +4*a(n-3) -2*a(n-6) -4*a(n-7) +2*a(n-9) for n>10. %F A256022 Empirical g.f.: x*(33 + 2*x + 51*x^2 - 20*x^3 - 24*x^4 - 56*x^5 - 66*x^6 + 12*x^7 + 36*x^8 + 2*x^9) / ((1 - x)*(1 - x - 4*x^3 - 4*x^4 - 4*x^5 - 2*x^6 + 2*x^7 + 2*x^8)). - _Colin Barker_, Dec 20 2018 %e A256022 Some solutions for n=4: %e A256022 ..1..0..1....0..1..1....0..1..1....1..1..0....0..1..1....1..1..1....1..1..1 %e A256022 ..1..1..1....1..1..0....1..1..1....1..1..1....1..1..1....1..0..1....1..1..1 %e A256022 ..1..1..0....1..1..1....1..0..1....1..1..1....1..1..1....1..1..1....1..0..1 %e A256022 ..0..1..1....1..1..1....1..1..1....1..1..0....0..1..1....1..1..0....1..1..1 %e A256022 ..1..1..1....0..1..1....1..1..1....0..1..1....1..1..1....0..1..1....0..1..1 %e A256022 ..1..0..1....1..1..1....1..0..1....1..1..1....1..0..1....1..0..1....1..1..0 %Y A256022 Column 1 of A256029. %K A256022 nonn %O A256022 1,1 %A A256022 _R. H. Hardin_, Mar 13 2015 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE