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A295526 Number of nX3 0..1 arrays with each 1 horizontally or vertically adjacent to 1, 2 or 4 1s. 1
4, 29, 147, 774, 4080, 21489, 113466, 598374, 3155426, 16642084, 87770692, 462903372, 2441353234, 12875695490, 67906455891, 358138834199, 1888825058236, 9961667898631, 52537860596653, 277084804179135, 1461345928848848 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A295531.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +3*a(n-2) +15*a(n-3) +17*a(n-4) +40*a(n-5) -6*a(n-6) -12*a(n-7) +45*a(n-8) -21*a(n-9) -66*a(n-10) +7*a(n-11) +6*a(n-12) -6*a(n-13) +6*a(n-14) +a(n-15) -3*a(n-16) +a(n-18)
EXAMPLE
Some solutions for n=5
..1..1..0. .1..1..0. .0..1..0. .1..1..1. .0..0..0. .0..1..0. .1..1..0
..0..1..0. .0..0..0. .0..1..1. .1..0..1. .0..1..1. .1..1..1. .0..1..1
..0..0..0. .1..1..0. .0..0..1. .1..1..0. .1..1..1. .1..1..1. .1..0..0
..0..0..0. .0..0..0. .1..0..1. .0..0..0. .1..1..0. .0..1..0. .1..1..1
..0..1..1. .0..1..1. .1..1..0. .1..1..0. .0..0..0. .0..0..0. .0..0..1
CROSSREFS
Cf. A295531.
Sequence in context: A273074 A247748 A295035 * A272373 A273247 A302260
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2017
STATUS
approved

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Last modified February 28 01:06 EST 2024. Contains 370379 sequences. (Running on oeis4.)