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A302815
Number of n X 3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 20, 75, 389, 1852, 8485, 41247, 196946, 931243, 4464289, 21314416, 101500589, 484945365, 2314846870, 11042132315, 52714123333, 251602109008, 1200668947009, 5730793024341, 27351896253430, 130538870872807, 623034403841625
OFFSET
1,1
COMMENTS
Column 3 of A302820.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +5*a(n-2) +36*a(n-3) -62*a(n-4) -116*a(n-5) -142*a(n-6) -78*a(n-7) +150*a(n-8) -100*a(n-9) +176*a(n-10) +272*a(n-11) +320*a(n-12) -256*a(n-14).
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..1. .0..1..1. .0..1..0. .0..1..0. .0..0..0. .0..0..1
..0..1..1. .1..1..0. .1..0..0. .1..1..1. .0..0..1. .0..1..0. .1..1..0
..1..1..1. .0..0..0. .1..0..1. .1..0..1. .0..1..1. .0..1..1. .0..1..0
..1..0..1. .0..0..0. .1..0..1. .0..0..1. .0..1..0. .0..0..0. .1..0..0
..0..0..0. .1..1..1. .1..0..0. .1..1..0. .0..0..0. .1..1..0. .0..0..1
CROSSREFS
Cf. A302820.
Sequence in context: A329174 A057333 A196432 * A196508 A121257 A145563
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 13 2018
STATUS
approved