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A243726 Number of length n+2 0..7 arrays with no three unequal elements in a row and no three equal elements in a row and new values 0..7 introduced in 0..7 order. 1
3, 6, 12, 25, 53, 116, 259, 594, 1389, 3323, 8095, 20113, 50814, 130631, 341024, 904241, 2431805, 6632342, 18324521, 51272228, 145153079, 415580431, 1202307183, 3512796459, 10356995364, 30795038625, 92273776218, 278450451781 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) - 90*a(n-3) + 105*a(n-4) + 441*a(n-5) - 652*a(n-6) - 1070*a(n-7) + 1491*a(n-8) + 1387*a(n-9) - 1198*a(n-10) - 840*a(n-11).
Empirical g.f.: x*(3 - 15*x - 30*x^2 + 211*x^3 + 103*x^4 - 1128*x^5 - 253*x^6 + 2756*x^7 + 852*x^8 - 2610*x^9 - 1371*x^10) / ((1 - 2*x)*(1 - x - x^2)*(1 - x - 3*x^2)*(1 - x - 4*x^2)*(1 - x - 5*x^2)*(1 - x - 7*x^2)). - Colin Barker, Nov 03 2018
EXAMPLE
Some solutions for n=6:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....1....1....0....0....1....0....1....1....1....1....0....1....0....0
..1....0....1....1....1....1....0....1....1....1....1....0....1....1....1....1
..1....0....0....0....1....0....1....0....0....2....0....0....1....2....1....1
..2....1....0....0....0....0....0....1....1....2....1....1....0....2....2....2
..2....0....1....2....0....2....0....1....1....3....0....0....1....0....1....2
..0....0....0....0....2....2....1....2....0....3....1....1....1....2....2....1
..2....2....0....0....2....0....0....2....0....4....1....1....2....0....1....1
CROSSREFS
Column 7 of A243729.
Sequence in context: A243723 A243724 A243725 * A243727 A243728 A243721
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 09 2014
STATUS
approved

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Last modified February 29 04:26 EST 2024. Contains 370401 sequences. (Running on oeis4.)