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A302267
Number of 3 X n 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 32, 153, 772, 3818, 19191, 96004, 481261, 2411557, 12086268, 60572976, 303579352, 1521476119, 7625336613, 38216661796, 191534345225, 959932146275, 4810989844333, 24111728148027, 120843206657400, 605642220203867
OFFSET
1,1
COMMENTS
Row 3 of A302265.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +14*a(n-2) -9*a(n-3) -54*a(n-4) -10*a(n-5) +65*a(n-6) +17*a(n-7) -8*a(n-8) -2*a(n-9) -31*a(n-10) -7*a(n-11) +9*a(n-12) for n>13.
EXAMPLE
Some solutions for n=5:
0 1 0 0 1 0 1 0 0 1 0 1 0 1 0 0 0 1 0 0
1 0 0 1 0 0 1 0 0 1 1 0 0 0 1 0 1 1 0 1
1 1 1 0 1 1 0 0 1 1 1 0 1 1 1 0 1 1 0 1
CROSSREFS
Cf. A302265.
Sequence in context: A301843 A332430 A302070 * A113154 A302966 A337367
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 04 2018
STATUS
approved