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A255991 Number of length n+7 0..1 arrays with at most one downstep in every 7 consecutive neighbor pairs. 1
93, 136, 207, 328, 530, 854, 1352, 2088, 3175, 4824, 7406, 11528, 18124, 28562, 44768, 69584, 107469, 165670, 256009, 397452, 619647, 967640, 1509297, 2347848, 3643074, 5646004, 8753601, 13591820, 21137644, 32901050, 51205059, 79628272, 123712139 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 7 of A255992.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) -a(n-2) +6*a(n-7) -5*a(n-8).
Empirical g.f.: x*(93 - 50*x + 28*x^2 + 50*x^3 + 81*x^4 + 122*x^5 + 174*x^6 - 320*x^7) / (1 - 2*x + x^2 - 6*x^7 + 5*x^8). - Colin Barker, Jan 25 2018
EXAMPLE
Some solutions for n=4:
..0....1....1....0....0....0....1....1....0....1....1....0....0....0....0....0
..0....0....1....0....0....1....1....1....1....0....1....1....0....1....1....0
..1....0....0....1....1....0....1....1....0....0....1....1....0....1....1....0
..0....0....0....0....0....0....0....1....0....0....1....1....0....0....1....0
..1....0....1....1....0....0....0....1....1....0....1....1....0....0....1....0
..1....1....1....1....1....1....0....1....1....1....0....1....0....0....1....1
..1....1....1....1....1....1....0....1....1....1....0....1....1....0....1....0
..1....1....1....1....1....1....0....0....1....1....0....1....1....1....1....0
..1....1....1....1....1....1....1....1....1....0....1....0....1....1....0....0
..1....1....0....1....1....0....1....1....1....0....1....0....1....1....1....0
..0....0....0....1....0....1....0....1....1....0....1....0....0....0....1....1
CROSSREFS
Cf. A255992.
Sequence in context: A249300 A153684 A048257 * A213114 A250366 A306540
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 13 2015
STATUS
approved

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Last modified February 26 04:47 EST 2024. Contains 370335 sequences. (Running on oeis4.)