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A228479 Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally. 1
5, 19, 127, 728, 4354, 25699, 152373, 902042, 5342712, 31639786, 187379548, 1109702480, 6571916787, 38920392611, 230495519461, 1365047364511, 8084124028133, 47876038862427, 283532896714060, 1679146925634733 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Same recurrences as A228285 except in addition this smaller one for this column.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + 15*a(n-2) + 16*a(n-3) - 11*a(n-4) - 20*a(n-5) + 19*a(n-6) - 8*a(n-7) + a(n-9).
Empirical g.f.: x*(5 + 4*x - 5*x^2 - 18*x^3 + 16*x^4 - 6*x^5 + x^7) / (1 - 3*x - 15*x^2 - 16*x^3 + 11*x^4 + 20*x^5 - 19*x^6 + 8*x^7 - x^9). - Colin Barker, Sep 11 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0..0....1..0..0..0..0....1..0..0..0..0....1..0..1..0..0
..0..0..0..1..0....0..0..0..0..1....0..0..0..0..0....0..0..0..1..0
..1..0..0..0..1....1..0..0..0..0....1..0..0..0..0....1..0..0..0..0
..0..0..1..0..0....0..0..0..0..0....0..0..0..1..0....0..1..0..0..1
CROSSREFS
Column 5 of A228482.
Sequence in context: A328060 A366340 A297389 * A354843 A187018 A193287
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 22 2013
STATUS
approved

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Last modified March 19 01:34 EDT 2024. Contains 370952 sequences. (Running on oeis4.)