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A300344 Number of n X 2 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 5
1, 2, 6, 15, 37, 90, 223, 550, 1355, 3341, 8237, 20307, 50064, 123426, 304290, 750185, 1849478, 4559634, 11241151, 27713513, 68323858, 168443083, 415273274, 1023799191, 2524036217, 6222664445, 15341124083, 37821433280, 93243546406 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A300350.

LINKS

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

Simon Plouffe, Conjectures of the OEIS, as of June 20, 2018.

FORMULA

Empirical: a(n) = a(n-1) + 2*a(n-2) + 3*a(n-3) + 2*a(n-4) + a(n-5).

Empirical g.f.: -x*(-2*x^4-2*x^3-2*x^2-x-1)/(-x^5-2*x^4-3*x^3-2*x^2-x+1). - Simon Plouffe, Jun 20 2018

EXAMPLE

Some solutions for n=5:

  0 0   0 1   0 0   0 1   0 0   0 0   0 1   0 0   0 0   0 1

  0 1   0 1   1 0   0 1   1 1   0 1   0 1   1 0   1 1   0 1

  1 0   1 0   1 0   0 1   0 1   1 0   0 1   1 1   0 1   0 1

  0 1   1 0   1 0   0 1   0 1   0 1   1 0   0 1   0 0   0 0

  1 1   1 1   1 1   0 0   0 1   0 1   1 0   0 1   1 1   1 1

CROSSREFS

Cf. A300350.

Sequence in context: A335903 A291414 A098790 * A018019 A331347 A306463

Adjacent sequences:  A300341 A300342 A300343 * A300345 A300346 A300347

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 03 2018

STATUS

approved

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Last modified May 16 15:15 EDT 2022. Contains 353706 sequences. (Running on oeis4.)