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A302665
Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
1, 14, 43, 194, 691, 2802, 10660, 41839, 161878, 630842, 2449576, 9528949, 37035686, 144004769, 559817133, 2176500315, 8461548011, 32896646099, 127893433256, 497218644961, 1933060065053, 7515258095114, 29217439753668, 113590121120145
OFFSET
1,2
COMMENTS
Column 3 of A302670.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +4*a(n-2) -11*a(n-3) -27*a(n-4) -12*a(n-5) +85*a(n-6) +22*a(n-7) -22*a(n-8) -108*a(n-9) +72*a(n-10) -80*a(n-11) +120*a(n-12) +64*a(n-14)
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..1. .0..1..1. .0..1..1. .0..0..1. .0..0..0. .0..1..1
..1..1..0. .1..1..1. .1..0..0. .0..0..1. .0..1..1. .1..1..0. .1..0..1
..1..0..0. .0..0..0. .1..0..0. .1..1..0. .0..0..1. .1..1..1. .1..1..1
..1..1..0. .1..0..1. .0..1..1. .1..0..0. .0..0..1. .0..0..0. .1..0..1
..0..0..1. .0..1..1. .1..0..0. .1..1..1. .0..1..1. .0..1..1. .0..1..0
CROSSREFS
Cf. A302670.
Sequence in context: A120714 A041378 A302219 * A041380 A151990 A156166
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 11 2018
STATUS
approved