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A297819
Number of nX4 0..1 arrays with every element equal to 1, 2 or 3 king-move adjacent elements, with upper left element zero.
1
2, 49, 146, 466, 1395, 4306, 13417, 41512, 128084, 395130, 1219746, 3768063, 11642142, 35964517, 111087880, 343131807, 1059922547, 3274149571, 10114014322, 31242498943, 96508734369, 298117843290, 920895161362, 2844676016212
OFFSET
1,1
COMMENTS
Column 4 of A297823.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) -7*a(n-2) +4*a(n-3) -a(n-5) -8*a(n-6) -35*a(n-7) +29*a(n-8) +32*a(n-9) +39*a(n-10) -35*a(n-11) -31*a(n-12) +5*a(n-13) +14*a(n-14) -3*a(n-15) -14*a(n-16) +2*a(n-17) +4*a(n-18) for n>21
EXAMPLE
Some solutions for n=7
..0..1..0..1. .0..1..1..1. .0..0..1..0. .0..1..0..0. .0..0..1..1
..1..0..1..0. .1..0..0..1. .0..1..1..0. .0..1..1..0. .1..1..0..0
..1..0..1..0. .0..1..1..0. .1..0..0..1. .1..0..0..1. .0..1..0..1
..0..0..1..0. .1..0..0..1. .1..1..1..1. .0..1..1..0. .0..1..0..1
..1..0..1..0. .0..1..1..1. .0..0..0..0. .1..0..0..0. .1..0..0..1
..1..0..1..1. .0..0..0..0. .0..1..1..0. .1..1..1..1. .1..1..1..1
..1..1..0..0. .1..1..1..1. .1..0..1..0. .0..0..0..0. .0..0..0..0
CROSSREFS
Cf. A297823.
Sequence in context: A058845 A041287 A057563 * A297989 A028479 A189389
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2018
STATUS
approved