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A297583 Number of 2 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s. 1
1, 5, 11, 17, 39, 93, 183, 373, 823, 1741, 3599, 7637, 16247, 34125, 71871, 152133, 321127, 676861, 1429135, 3017909, 6367607, 13437869, 28367775, 59874021, 126360711, 266707549, 562939183, 1188130069, 2507681687, 5292853517 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 4*a(n-3) + 2*a(n-4).
Empirical g.f.: x*(1 + 4*x + 6*x^2 + 2*x^3) / (1 - x - 4*x^3 - 2*x^4). - Colin Barker, Mar 01 2019
EXAMPLE
Some solutions for n=7:
..0..0..0..0..0..0..0. .0..1..0..0..0..1..0. .1..1..1..0..0..0..0
..0..1..1..0..0..1..1. .1..0..0..0..0..0..1. .1..0..1..0..0..1..1
CROSSREFS
Row 2 of A297582.
Sequence in context: A277290 A085634 A157478 * A356756 A088903 A094205
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 01 2018
STATUS
approved

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Last modified February 28 01:06 EST 2024. Contains 370379 sequences. (Running on oeis4.)