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 A268738 Number of nX6 binary arrays with some 1 horizontally or vertically adjacent to some other 1 exactly once. 1
 20, 420, 7831, 128232, 1971414, 29134076, 418632185, 5894815754, 81718671716, 1119014223138, 15171181272721, 203998929406004, 2724149465085496, 36163754541884778, 477648079847735215, 6280858615510607492 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 6 of A268740. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 16*a(n-1) +60*a(n-2) -1148*a(n-3) -3346*a(n-4) +16272*a(n-5) +36588*a(n-6) -104246*a(n-7) -147989*a(n-8) +349140*a(n-9) +217324*a(n-10) -591448*a(n-11) -19320*a(n-12) +431032*a(n-13) -151921*a(n-14) -73194*a(n-15) +41684*a(n-16) +2552*a(n-17) -3594*a(n-18) +148*a(n-19) +100*a(n-20) -4*a(n-21) -a(n-22) EXAMPLE Some solutions for n=4 ..0..0..0..0..1..0. .0..0..0..0..1..0. .1..0..0..0..0..1. .0..0..1..1..0..0 ..0..0..1..0..0..0. .0..1..0..0..0..0. .0..1..0..0..0..0. .0..1..0..0..1..0 ..1..0..0..0..0..0. .1..0..0..0..0..0. .1..0..0..1..0..0. .0..0..0..0..0..0 ..0..0..1..1..0..0. .1..0..1..0..1..0. .1..0..0..0..0..1. .0..0..0..0..0..1 CROSSREFS Cf. A268740. Sequence in context: A068772 A230349 A158601 * A215290 A130832 A180810 Adjacent sequences:  A268735 A268736 A268737 * A268739 A268740 A268741 KEYWORD nonn AUTHOR R. H. Hardin, Feb 12 2016 STATUS approved

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Last modified October 19 15:49 EDT 2018. Contains 316365 sequences. (Running on oeis4.)