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A301395
Number of nX3 0..1 arrays with every element equal to 2, 3, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
0, 2, 3, 13, 44, 156, 554, 1963, 6964, 24699, 87617, 310815, 1102602, 3911438, 13875683, 49223528, 174618908, 619455124, 2197497772, 7795555028, 27654489341, 98103442446, 348018917203, 1234586307769, 4379656611234, 15536695906316
OFFSET
1,2
COMMENTS
Column 3 of A301400.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +2*a(n-2) -a(n-3) +3*a(n-4) +3*a(n-5) -8*a(n-6) -13*a(n-7) -13*a(n-8) -7*a(n-9) -8*a(n-10) -7*a(n-11) -a(n-12) +a(n-13) -2*a(n-14) +a(n-15)
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..0. .0..0..1. .0..0..0. .0..0..1. .0..0..1. .0..0..0
..0..1..1. .0..0..1. .0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..1..0
..0..1..1. .0..1..1. .0..0..0. .0..0..0. .0..1..1. .0..1..0. .1..1..0
..0..1..0. .0..1..0. .1..1..0. .1..1..0. .0..0..0. .0..0..0. .1..0..0
..0..0..0. .0..0..0. .1..0..0. .1..0..0. .0..0..0. .0..0..0. .0..0..0
CROSSREFS
Cf. A301400.
Sequence in context: A235626 A164133 A226938 * A206776 A275556 A214888
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 20 2018
STATUS
approved