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A253132 Number of length 4+2 0..n arrays with the sum of medians of adjacent triples multiplied by some arrangement of +-1 equal to zero 1
40, 393, 2058, 7257, 19990, 46945, 98124, 187593, 335106, 566597, 915078, 1423385, 2144128, 3140689, 4491642, 6289609, 8642310, 11679353, 15549300, 20420721, 26492194, 33986741, 43152838, 54278609, 67682648, 83714937, 102776362 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 4 of A253129
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -3*a(n-2) +5*a(n-3) -12*a(n-4) +12*a(n-5) -10*a(n-6) +18*a(n-7) -18*a(n-8) +10*a(n-9) -12*a(n-10) +12*a(n-11) -5*a(n-12) +3*a(n-13) -3*a(n-14) +a(n-15)
Empirical for n mod 3 = 0: a(n) = (2/15)*n^6 + (1273/405)*n^5 + (298/27)*n^4 + (601/81)*n^3 + (143/15)*n^2 + (238/45)*n + 1
Empirical for n mod 3 = 1: a(n) = (2/15)*n^6 + (1273/405)*n^5 + (298/27)*n^4 + (203/27)*n^3 + (4001/405)*n^2 + (32/5)*n + (17/9)
Empirical for n mod 3 = 2: a(n) = (2/15)*n^6 + (1273/405)*n^5 + (298/27)*n^4 + (601/81)*n^3 + (3781/405)*n^2 + (218/45)*n + (73/81)
EXAMPLE
Some solutions for n=8
..8....0....8....3....6....1....3....8....3....1....2....0....1....7....3....6
..2....2....1....5....2....1....3....0....1....2....3....1....4....3....3....2
..4....8....3....4....3....7....2....0....0....0....3....6....2....1....0....3
..2....0....1....5....8....1....4....6....3....0....5....7....6....7....5....7
..6....2....0....8....8....4....5....5....8....1....7....1....2....1....6....5
..6....7....8....6....1....4....2....0....3....8....2....0....4....8....4....3
CROSSREFS
Sequence in context: A229716 A221820 A301528 * A293969 A168192 A251129
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 27 2014
STATUS
approved

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Last modified May 29 22:36 EDT 2024. Contains 372954 sequences. (Running on oeis4.)