A243388 - OEIS

A243388

Number of length n+3 0..7 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..7 introduced in 0..7 order

14, 46, 174, 737, 3435, 17402, 94907, 552660, 3409915, 22122613, 149763921, 1050072965, 7573195764, 55841366002, 418835322674, 3182422956259, 24417445081110, 188710025928915, 1466319454136469, 11439104238553624

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OFFSET

1,1

COMMENTS

Column 7 of A243389

LINKS

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

FORMULA

Empirical: a(n) = 29*a(n-1) -349*a(n-2) +2287*a(n-3) -9065*a(n-4) +23201*a(n-5) -41175*a(n-6) +55373*a(n-7) -60041*a(n-8) +53229*a(n-9) -39663*a(n-10) +25113*a(n-11) -13424*a(n-12) +6232*a(n-13) -2386*a(n-14) +806*a(n-15) -209*a(n-16) +49*a(n-17) -7*a(n-18) +a(n-19)

EXAMPLE

Some solutions for n=3

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

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

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

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

..3....2....1....2....4....0....2....3....2....3....3....0....1....2....0....0

..0....1....2....0....3....0....3....4....0....4....1....1....0....3....1....0

CROSSREFS

Sequence in context: A242580 A243386 A243387 * A242581 A242582 A242583

Adjacent sequences: A243385 A243386 A243387 * A243389 A243390 A243391

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 04 2014

STATUS

approved