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A318425
Number of nX3 0..1 arrays with every element unequal to 1, 2, 3 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1
1, 16, 36, 147, 417, 1353, 4095, 12853, 39489, 123210, 380280, 1182026, 3659119, 11351061, 35179874, 109070933, 338113844, 1048217069, 3249453631, 10073853147, 31229167798, 96814146538, 300130174990, 930430509302, 2884410320136
OFFSET
1,2
COMMENTS
Column 3 of A318430.
LINKS
FORMULA
Empirical: a(n) = 9*a(n-2) +11*a(n-3) -14*a(n-4) -32*a(n-5) -29*a(n-6) -51*a(n-7) +33*a(n-8) +116*a(n-9) +18*a(n-10) +70*a(n-11) +92*a(n-12) -22*a(n-13) -12*a(n-16) +4*a(n-17) for n>20
EXAMPLE
Some solutions for n=5
..0..1..0. .0..1..0. .0..1..1. .0..0..0. .0..1..0. .0..1..0. .0..1..0
..1..1..1. .1..1..1. .0..1..0. .1..1..0. .0..1..1. .0..1..0. .0..1..1
..0..0..0. .0..0..0. .1..1..0. .1..1..1. .1..1..1. .1..1..1. .1..0..1
..0..1..1. .0..0..1. .1..1..0. .0..0..0. .0..0..0. .0..1..1. .1..1..0
..1..1..0. .1..1..0. .0..1..0. .1..0..1. .1..0..1. .0..1..0. .0..1..0
CROSSREFS
Cf. A318430.
Sequence in context: A069262 A076956 A075369 * A273373 A264546 A218523
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 26 2018
STATUS
approved