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A297577
Number of n X 3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s.
1
3, 11, 36, 102, 370, 1243, 3854, 13078, 43861, 141109, 468638, 1561065, 5101698, 16842125, 55830567, 183595621, 605376713, 2001499842, 6596762626, 21752445702, 71828204711, 236917416288, 781388833534, 2578812375049, 8507768092491
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OFFSET
1,1
LINKS
R. H. Hardin,
Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) + 19*a(n-3) + 4*a(n-4) - 17*a(n-5) - 8*a(n-6).
Empirical g.f.: x*(3 + 8*x + 19*x^2 - 13*x^3 - 25*x^4 - 8*x^5) / ((1 - x)*(1 - 2*x^2 - 21*x^3 - 25*x^4 - 8*x^5)). -
Colin Barker
, Mar 01 2019
EXAMPLE
Some solutions for n=7:
..0..0..0. .1..0..1. .0..0..0. .0..0..0. .0..0..0. .1..1..0. .0..0..0
..0..1..1. .1..1..1. .0..1..1. .1..0..1. .1..0..0. .0..0..0. .0..0..0
..0..0..0. .0..0..0. .0..0..0. .0..1..1. .1..1..0. .1..0..1. .0..1..1
..1..0..1. .0..1..0. .0..0..1. .0..0..1. .1..0..1. .1..1..1. .0..0..0
..1..1..1. .1..0..0. .1..1..1. .0..0..0. .1..0..1. .0..0..0. .1..0..1
..0..0..0. .1..0..1. .0..0..1. .0..1..0. .1..1..0. .0..0..1. .0..1..1
..0..1..1. .1..1..1. .0..0..0. .0..0..1. .1..0..0. .0..1..0. .0..0..1
CROSSREFS
Column 3 of
A297582
.
Sequence in context:
A119092
A119177
A213679
*
A119126
A119088
A296391
Adjacent sequences:
A297574
A297575
A297576
*
A297578
A297579
A297580
KEYWORD
nonn
AUTHOR
R. H. Hardin
, Jan 01 2018
STATUS
approved