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A268765
Number of nX7 binary arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once.
1
38, 595, 8500, 99057, 1129042, 12111209, 127676872, 1312123185, 13311824510, 133228716170, 1321110678618, 12988699400546, 126844585914726, 1231361200765123, 11893679949360102, 114371480492930683
OFFSET
1,1
COMMENTS
Column 7 of A268766.
LINKS
FORMULA
Empirical: a(n) = 12*a(n-1) +64*a(n-2) -942*a(n-3) -1476*a(n-4) +26868*a(n-5) +2249*a(n-6) -376788*a(n-7) +333472*a(n-8) +2686292*a(n-9) -4376424*a(n-10) -8985248*a(n-11) +21881197*a(n-12) +12658940*a(n-13) -55768960*a(n-14) +923990*a(n-15) +80699088*a(n-16) -25850884*a(n-17) -69171189*a(n-18) +34934900*a(n-19) +34833816*a(n-20) -22502076*a(n-21) -9502460*a(n-22) +7752808*a(n-23) +1023260*a(n-24) -1356480*a(n-25) +55136*a(n-26) +94080*a(n-27) -14400*a(n-28)
EXAMPLE
Some solutions for n=4
..1..0..0..0..0..1..0. .0..0..0..0..0..1..1. .0..0..0..0..1..0..0
..0..0..0..1..0..0..1. .1..0..1..0..0..0..0. .1..0..1..0..0..1..0
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0
..0..0..1..0..1..0..0. .0..1..0..0..1..0..0. .0..0..1..0..0..0..1
CROSSREFS
Cf. A268766.
Sequence in context: A088891 A159784 A243820 * A202715 A094034 A020931
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 13 2016
STATUS
approved