

A255112


Number of length n+5 0..2 arrays with at most one downstep in every n consecutive neighbor pairs.


1



729, 1791, 2907, 4429, 6582, 9297, 12662, 16779, 21765, 27753, 34893, 43353, 53320, 65001, 78624, 94439, 112719, 133761, 157887, 185445, 216810, 252385, 292602, 337923, 388841, 445881, 509601, 580593, 659484, 746937, 843652, 950367, 1067859
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OFFSET

1,1


COMMENTS

Row 5 of A255107.


LINKS

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


FORMULA

Empirical: a(n) = (1/120)*n^5 + (1/3)*n^4 + (115/24)*n^3 + (889/6)*n^2 + (3867/10)*n + 111 for n>3.
Empirical g.f.: x*(729  2583*x + 3096*x^2  728*x^3  1272*x^4 + 591*x^5 + 618*x^6  594*x^7 + 144*x^8) / (1  x)^6.  Colin Barker, Jan 24 2018


EXAMPLE

Some solutions for n=4:
..0....2....1....0....1....2....1....1....0....1....0....2....1....0....0....2
..2....0....1....1....0....2....1....0....2....0....2....2....0....2....2....0
..2....0....1....0....0....1....2....1....1....0....0....0....0....2....2....0
..0....2....1....0....1....1....1....1....1....2....0....1....0....2....2....0
..0....2....0....1....2....2....1....2....1....2....2....1....0....2....1....0
..2....2....0....2....2....2....1....2....1....2....2....1....0....0....1....0
..2....0....0....0....1....0....2....1....0....2....2....2....0....1....1....2
..1....1....1....1....2....1....0....1....0....2....1....0....0....1....2....2
..2....1....1....2....2....1....2....2....0....0....2....0....1....1....1....1


CROSSREFS

Cf. A255107.
Sequence in context: A043455 A267697 A232925 * A255627 A139308 A295024
Adjacent sequences: A255109 A255110 A255111 * A255113 A255114 A255115


KEYWORD

nonn


AUTHOR

R. H. Hardin, Feb 14 2015


STATUS

approved



