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A261376
Number of (n+2)X(4+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00001011 00010101 or 01010101.
1
97, 157, 424, 1040, 2282, 5254, 12500, 28885, 66332, 154413, 358786, 830309, 1923846, 4465820, 10349526, 23993883, 55620850, 129004265, 298983410, 693371845, 1607151330, 3727183505, 8638778942, 20034575762, 46436324264
OFFSET
1,1
COMMENTS
Column 4 of A261380.
LINKS
FORMULA
Empirical: a(n) = a(n-2) +18*a(n-4) +32*a(n-6) -7*a(n-8) -33*a(n-10) +13*a(n-12) +25*a(n-14) -28*a(n-16) +9*a(n-18) -a(n-20) for n>22
EXAMPLE
Some solutions for n=4
..1..0..1..0..1..0....1..0..0..0..1..0....1..0..1..0..1..0....0..1..0..1..0..0
..0..1..0..1..0..1....0..1..0..1..0..1....0..1..0..1..0..0....0..0..1..0..1..0
..1..0..1..0..0..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..0..1..0..1....1..0..1..0..1..0
..1..0..1..0..1..0....0..0..1..0..0..0....1..0..1..0..1..0....0..1..0..0..0..1
..0..1..0..1..0..1....0..1..0..1..0..1....0..1..0..1..0..1....1..0..1..0..1..0
CROSSREFS
Cf. A261380.
Sequence in context: A142528 A139500 A344481 * A142094 A142212 A108655
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 17 2015
STATUS
approved