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A297521 Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 3 neighboring 1s. 1
1, 11, 49, 128, 363, 1408, 5079, 16104, 52308, 180643, 616299, 2045926, 6825942, 23061538, 77737769, 260557844, 874178204, 2940510392, 9886875406, 33203436061, 111529068093, 374823089239, 1259590086969, 4231808883913, 14217990538402 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 3 of A297519.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = a(n-1) +a(n-2) +10*a(n-3) +37*a(n-4) +23*a(n-5) +21*a(n-6) -25*a(n-7) -40*a(n-8) -44*a(n-9) +17*a(n-11) +5*a(n-12)

EXAMPLE

Some solutions for n=7

..0..0..0..0..0..0..1. .0..0..0..0..0..0..0. .0..0..0..0..0..1..1

..0..1..0..0..0..1..0. .1..1..0..0..0..1..0. .0..0..0..0..0..0..0

..0..1..1..1..0..0..0. .1..0..1..0..1..0..0. .0..0..0..0..1..1..0

CROSSREFS

Cf. A297519.

Sequence in context: A226676 A101992 A160671 * A295420 A003063 A124857

Adjacent sequences:  A297518 A297519 A297520 * A297522 A297523 A297524

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 31 2017

STATUS

approved

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Last modified June 14 21:27 EDT 2021. Contains 345041 sequences. (Running on oeis4.)