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A242544 Number of length n+3 0..3 arrays with no four elements in a row with pattern aabb (possibly a=b) and new values 0..3 introduced in 0..3 order 1
13, 42, 150, 554, 2072, 7808, 29536, 111878, 423969, 1607058, 6092367, 23097242, 87566957, 331989206, 1258663594, 4771951574, 18091832688, 68591328768, 260049450816, 985922294306, 3737915147525, 14171512153838, 53728281674119 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A242549

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +10*a(n-3) -2*a(n-4) -12*a(n-5) -9*a(n-6) -18*a(n-7) -9*a(n-8).

Empirical: G.f.: -x*(-13+10*x-21*x^2+50*x^3+88*x^4+78*x^5+99*x^6+42*x^7) / ( (x^2+x-1)*(3*x^2+3*x-1)*(3*x^2+1)*(x^2+1) ). - R. J. Mathar, May 18 2014

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A162265 A233298 A243028 * A301539 A240517 A074022

Adjacent sequences:  A242541 A242542 A242543 * A242545 A242546 A242547

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 17 2014

STATUS

approved

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Last modified April 10 22:05 EDT 2021. Contains 342856 sequences. (Running on oeis4.)