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A230509 Number of n X 2 0..7 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 8, and upper left element zero. 2
0, 0, 0, 2, 8, 32, 118, 440, 1664, 6354, 24360, 93440, 358246, 1372824, 5259424, 20147874, 77183048, 295680992, 1132742102, 4339515256, 16624624832, 63688678130, 243990165864, 934721535168, 3580899428294, 13718353772632 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
Column 2 of A230513.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) - 4*a(n-2) - 5*a(n-3) + 9*a(n-4) + 12*a(n-5).
Empirical g.f.: 2*x^4*(1 - x) / (1 - 5*x + 4*x^2 + 5*x^3 - 9*x^4 - 12*x^5). - Colin Barker, Mar 17 2018
EXAMPLE
All solutions for n=4:
..0..7....0..1
..1..6....7..2
..2..5....6..3
..3..4....5..4
CROSSREFS
Cf. A230513.
Sequence in context: A145682 A363109 A289451 * A099752 A230393 A230529
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 21 2013
STATUS
approved

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Last modified June 20 13:44 EDT 2024. Contains 373527 sequences. (Running on oeis4.)