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A255629 Number of length n+7 0..2 arrays with at most two downsteps in every n consecutive neighbor pairs 1
6561, 19683, 59049, 152106, 322078, 602886, 1047141, 1706242, 2653107, 3977859, 5790140, 8221629, 11428785, 15595837, 20938044, 27705249, 36185752, 46710528, 59657817, 75458114, 94599588, 117633960, 145182871, 177944772, 216702369 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A255622

LINKS

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

FORMULA

Empirical: a(n) = (1/40320)*n^8 + (23/10080)*n^7 + (239/2880)*n^6 + (1541/144)*n^5 + (920887/5760)*n^4 + (442121/1440)*n^3 + (42883817/3360)*n^2 - (2307073/56)*n + 29319 for n>5

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

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

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

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

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

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

CROSSREFS

Cf. A255622

Sequence in context: A046321 A043456 A255114 * A017080 A017164 A017380

Adjacent sequences:  A255626 A255627 A255628 * A255630 A255631 A255632

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 28 2015

STATUS

approved

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Last modified December 5 17:28 EST 2021. Contains 349557 sequences. (Running on oeis4.)