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A261109
Number of (n+2) X (4+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010001 00010101 or 01010101.
1
97, 206, 566, 1498, 3908, 10268, 27030, 70980, 186290, 489516, 1286458, 3379154, 8876106, 23319066, 61261972, 160934256, 422777430, 1110660098, 2917747758, 7665011686, 20136272074, 52898777022, 138967021622, 365071414304
OFFSET
1,1
COMMENTS
Column 4 of A261113.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +6*a(n-3) +8*a(n-4) +10*a(n-5) +11*a(n-6) +7*a(n-7) +a(n-8) -7*a(n-9) -6*a(n-10) +a(n-11) +3*a(n-12) +a(n-13) for n>14.
EXAMPLE
Some solutions for n=4
..0..0..1..0..0..0....0..1..0..0..0..1....0..0..0..1..0..0....0..0..1..0..1..0
..0..0..0..1..0..1....1..0..1..0..1..0....1..0..1..0..1..0....0..0..0..1..0..0
..1..0..1..0..1..0....0..1..0..1..0..1....0..1..0..1..0..1....1..0..1..0..1..0
..0..1..0..1..0..1....1..0..1..0..1..0....1..0..1..0..1..0....0..1..0..0..0..1
..1..0..1..0..0..0....0..1..0..1..0..1....0..1..0..1..0..0....1..0..1..0..1..0
..0..0..0..1..0..1....0..0..1..0..1..0....1..0..1..0..1..0....0..0..0..1..0..0
CROSSREFS
Cf. A261113.
Sequence in context: A176011 A157410 A142504 * A142689 A142908 A006310
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 08 2015
STATUS
approved