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A262316
Number of (n+2)X(4+2) 0..1 arrays with each row and column divisible by 7, read as a binary number with top and left being the most significant bits.
1
10, 27, 133, 1618, 6043, 42661, 683218, 4276587, 39384421, 511294354, 4145349211, 40383402661, 455304705490, 4148740666347, 41070560499493, 433051832901778, 4157030255637403, 41395269270386341, 423634866109163218
OFFSET
1,1
COMMENTS
Column 4 of A262319.
LINKS
FORMULA
Empirical: a(n) = 13*a(n-1) -30*a(n-2) +775*a(n-3) -10075*a(n-4) +23250*a(n-5) -187265*a(n-6) +2434445*a(n-7) -5617950*a(n-8) +18375455*a(n-9) -238880915*a(n-10) +551263650*a(n-11) -585288123*a(n-12) +7608745599*a(n-13) -17558643690*a(n-14) -12851058675*a(n-15) +167063762775*a(n-16) -385531760250*a(n-17) +757921180765*a(n-18) -9852975349945*a(n-19) +22737635422950*a(n-20) -1115961555955*a(n-21) +14507500227415*a(n-22) -33478846678650*a(n-23) -69403913471776*a(n-24) +902250875133088*a(n-25) -2082117404153280*a(n-26) -67517783528000*a(n-27) +877731185864000*a(n-28) -2025533505840000*a(n-29)
EXAMPLE
Some solutions for n=4
..0..1..0..1..0..1....1..1..0..0..0..1....1..1..1..1..1..1....1..1..1..0..0..0
..1..0..1..0..1..0....0..1..0..1..0..1....0..1..1..1..0..0....0..1..0..1..0..1
..1..0..0..0..1..1....0..0..0..1..1..1....0..0..0..1..1..1....0..0..1..1..1..0
..1..0..1..0..1..0....0..0..0..1..1..1....0..0..0..0..0..0....0..0..0..1..1..1
..0..1..0..1..0..1....1..0..0..0..1..1....1..0..0..0..1..1....1..0..1..0..1..0
..0..1..1..1..0..0....1..1..0..0..0..1....1..1..1..0..0..0....1..1..0..0..0..1
CROSSREFS
Cf. A262319.
Sequence in context: A179546 A119548 A219629 * A362737 A262919 A370672
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 17 2015
STATUS
approved