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A297945 Number of n X 2 0..1 arrays with every element equal to 1, 2, 3 or 5 king-move adjacent elements, with upper left element zero. 8
1, 4, 18, 52, 174, 604, 2048, 6948, 23652, 80488, 273840, 931808, 3170824, 10789824, 36716272, 124940880, 425158448, 1446762336, 4923157280, 16752910976, 57008139808, 193991844032, 660130925440, 2246346198336, 7644046147776 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A297951.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) + 2*a(n-3) - 6*a(n-4) - 4*a(n-5) for n > 6.

Empirical g.f.: x*(1 + 4*x^2 - 14*x^3 + 4*x^5) / (1 - 4*x + 2*x^2 - 2*x^3 + 6*x^4 + 4*x^5). - Colin Barker, Feb 18 2018

EXAMPLE

Some solutions for n=7:

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

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

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

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

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

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

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

CROSSREFS

Cf. A297951.

Sequence in context: A300876 A301486 A284607 * A320544 A020644 A182031

Adjacent sequences:  A297942 A297943 A297944 * A297946 A297947 A297948

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 09 2018

STATUS

approved

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Last modified May 25 19:07 EDT 2019. Contains 323576 sequences. (Running on oeis4.)