A302630 - OEIS

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A302630

Number of nX3 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

3, 9, 8, 19, 42, 82, 189, 469, 1029, 2372, 5661, 12788, 29440, 69193, 158299, 364581, 849888, 1955567, 4508226, 10463966, 24138613, 55695301, 128985441, 297870624, 687700145, 1590857932, 3675434388, 8488858425, 19626303139, 45350971169

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OFFSET

1,1

COMMENTS

Column 3 of A302635.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = a(n-1) +9*a(n-3) -4*a(n-4) +2*a(n-5) -10*a(n-6) +4*a(n-7) +4*a(n-9) for n>13

EXAMPLE

Some solutions for n=5

..0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..0..1