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A299216
Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.
2
1, 12, 22, 81, 307, 1201, 5066, 21292, 90443, 387999, 1664166, 7150000, 30748156, 132241210, 568885960, 2447521291, 10530203290, 45306613634, 194935607759, 838730766281, 3608741827447, 15527073831286, 66807269901814
OFFSET
1,2
COMMENTS
Column 3 of A299221.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +7*a(n-2) +2*a(n-3) -27*a(n-4) -27*a(n-5) +3*a(n-6) -101*a(n-7) -69*a(n-8) +201*a(n-9) +105*a(n-10) -137*a(n-11) -32*a(n-12) +47*a(n-13) +21*a(n-14) -17*a(n-15) +37*a(n-16) +33*a(n-17) -12*a(n-18) -4*a(n-19) for n>20
EXAMPLE
Some solutions for n=5
..0..0..1. .0..1..0. .0..0..1. .0..1..0. .0..1..1. .0..0..1. .0..1..0
..0..1..1. .0..0..0. .0..1..1. .0..0..0. .0..0..1. .0..0..0. .1..1..1
..0..0..0. .0..0..0. .0..0..0. .0..0..1. .1..1..1. .1..0..0. .0..0..1
..1..0..1. .1..1..0. .0..0..0. .1..1..1. .0..1..0. .0..0..1. .1..0..1
..1..1..1. .1..0..0. .1..0..1. .0..1..0. .1..1..1. .0..0..0. .1..1..1
CROSSREFS
Cf. A299221.
Sequence in context: A115703 A014633 A298323 * A227072 A066458 A246342
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 05 2018
STATUS
approved