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 A260009 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000101 00010101 or 01010101. 1
 49, 98, 252, 578, 1232, 2738, 6262, 14112, 31500, 70688, 159198, 357858, 803428, 1805000, 4056988, 9116450, 20482308, 46022418, 103415312, 232373682, 522131898, 1173216800, 2636206832, 5923508168, 13309979250, 29907242450, 67201004772 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) + a(n-3) + 3*a(n-4) - 5*a(n-5) - a(n-6) - a(n-8) + a(n-9) for n>10. Empirical g.f.: x*(49 + 56*x^2 + 25*x^3 - 169*x^4 - 27*x^5 - 9*x^6 - 20*x^7 + 33*x^8 - x^9) / ((1 - 2*x - x^2 + x^3)*(1 + x^2 - 2*x^4 - x^6)). - Colin Barker, Dec 27 2018 EXAMPLE Some solutions for n=4: ..1..0..0..0....1..0..1..0....0..0..0..0....0..1..0..1....0..1..0..0 ..0..1..0..0....0..1..0..1....0..0..0..1....0..0..1..0....1..0..1..0 ..1..0..1..0....1..0..1..0....1..0..1..0....0..1..0..1....0..1..0..0 ..0..1..0..1....0..1..0..1....0..1..0..1....1..0..1..0....1..0..1..0 ..0..0..1..0....1..0..1..0....0..0..1..0....0..1..0..1....0..1..0..0 ..0..0..0..1....0..1..0..1....0..0..0..1....1..0..0..0....0..0..1..0 CROSSREFS Column 2 of A260015. Sequence in context: A043394 A044519 A031484 * A114013 A235578 A161689 Adjacent sequences: A260006 A260007 A260008 * A260010 A260011 A260012 KEYWORD nonn AUTHOR R. H. Hardin, Jul 13 2015 STATUS approved

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Last modified October 1 11:02 EDT 2023. Contains 365819 sequences. (Running on oeis4.)