

A255114


Number of length n+7 0..2 arrays with at most one downstep in every n consecutive neighbor pairs.


1



6561, 14849, 19338, 23463, 29147, 38010, 49611, 63075, 78552, 96210, 116236, 138837, 164241, 192698, 224481, 259887, 299238, 342882, 391194, 444577, 503463, 568314, 639623, 717915, 803748, 897714, 1000440, 1112589, 1234861, 1367994
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OFFSET

1,1


COMMENTS

Row 7 of A255107.


LINKS

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


FORMULA

Empirical: a(n) = (1/120)*n^5 + (5/12)*n^4 + (187/24)*n^3 + (7393/12)*n^2 + (20667/10)*n + 1143 for n>5.
Empirical g.f.: x*(6561  24517*x + 28659*x^2  1050*x^3  20126*x^4 + 11682*x^5  2967*x^6 + 3385*x^7  168*x^8  2466*x^9 + 1008*x^10) / (1  x)^6.  Colin Barker, Jan 24 2018


EXAMPLE

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


CROSSREFS

Cf. A255107.
Sequence in context: A043488 A046321 A043456 * A255629 A017080 A017164
Adjacent sequences: A255111 A255112 A255113 * A255115 A255116 A255117


KEYWORD

nonn


AUTHOR

R. H. Hardin, Feb 14 2015


STATUS

approved



