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A222919 Number of n X 1 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order. 2
1, 2, 4, 12, 41, 158, 663, 2944, 13537, 63551, 301968, 1444795, 6940099, 33411718, 161058633, 776930015, 3749357128, 18098055047, 87370273487, 421820387606, 2036618058597, 9833358788859, 47478828272736, 229245800095323 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 1 of A222924.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) - 7*a(n-2) - 20*a(n-3) + 10*a(n-4) + 24*a(n-5) + 8*a(n-6) for n>8.

Empirical g.f.: x*(1 + x)*(1 - 6*x + 3*x^2 + 15*x^3 - 9*x^5 - 3*x^6) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 4*x - 4*x^2)). - Colin Barker, Mar 16 2018

EXAMPLE

All solutions for n=3:

..0....0....0....0

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

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

CROSSREFS

Cf. A222924.

Sequence in context: A330679 A342225 A218144 * A264760 A090959 A244035

Adjacent sequences:  A222916 A222917 A222918 * A222920 A222921 A222922

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 09 2013

STATUS

approved

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Last modified January 22 21:47 EST 2022. Contains 350504 sequences. (Running on oeis4.)