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A302159
Number of nX4 0..1 arrays with every element equal to 0, 1 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
5, 17, 12, 29, 73, 156, 361, 865, 1970, 4530, 10571, 24394, 56204, 130230, 301221, 695541, 1608549, 3720177, 8597848, 19876759, 45959426, 106246321, 245619039, 567865144, 1312830532, 3035049693, 7016724012, 16221856134, 37502724170
OFFSET
1,1
COMMENTS
Column 4 of A302163.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +6*a(n-3) -4*a(n-5) -7*a(n-6) -a(n-7) +3*a(n-8) +2*a(n-9) -a(n-10) -4*a(n-11) -3*a(n-12) +a(n-13) +2*a(n-14) +2*a(n-15) for n>19
EXAMPLE
Some solutions for n=5
..0..0..1..1. .0..0..1..1. .0..1..0..1. .0..1..0..1. .0..1..0..1
..0..1..0..1. .0..1..0..1. .0..1..0..0. .1..1..0..1. .0..1..1..0
..0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..0. .1..0..1..0
..1..1..0..0. .0..1..0..0. .0..1..0..1. .0..1..0..1. .1..0..1..0
..0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1. .1..0..0..1
CROSSREFS
Cf. A302163.
Sequence in context: A180024 A356403 A178197 * A070848 A213738 A060829
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 02 2018
STATUS
approved