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A197369 Number of n X 4 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,4,1,0,1 for x=0,1,2,3,4. 1
1, 7, 45, 161, 899, 4023, 19387, 92169, 436539, 2077281, 9861263, 46848707, 222547181, 1057107041, 5021579939, 23853406065, 113308835575, 538241104209, 2556757711375, 12145141483565, 57691981461499, 274049091332625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Every 0 is next to 0 2's, every 1 is next to 1 4's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 1's.

Column 4 of A197373.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +10*a(n-2) +18*a(n-3) -7*a(n-4) -33*a(n-5) -58*a(n-6) +13*a(n-7) +22*a(n-8) -31*a(n-9) +18*a(n-10) -3*a(n-11).

EXAMPLE

Some solutions containing all values 0 to 4 for n=5

..0..0..1..2....0..0..0..0....0..0..1..2....2..1..0..0....0..0..1..2

..0..1..4..1....0..0..0..0....0..1..4..1....1..4..1..0....0..1..4..1

..3..0..1..0....0..1..0..3....3..0..1..0....0..1..0..0....3..0..1..0

..0..0..3..0....1..4..1..0....0..0..3..0....3..0..0..3....0..0..0..3

..0..3..0..0....2..1..0..0....0..0..0..0....0..0..3..0....0..0..0..0

CROSSREFS

Cf. A197373.

Sequence in context: A212105 A208826 A206808 * A059937 A278682 A342568

Adjacent sequences:  A197366 A197367 A197368 * A197370 A197371 A197372

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 14 2011

STATUS

approved

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Last modified September 24 21:05 EDT 2021. Contains 347651 sequences. (Running on oeis4.)