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A250562
Number of length 3+2 0..n arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero
1
14, 83, 302, 761, 1648, 3125, 5446, 8843, 13662, 20173, 28836, 39973, 54102, 71647, 93210, 119221, 150416, 187305, 230650, 281051, 339378, 406245, 482652, 569257, 667098, 776983, 900018, 1036969, 1189124, 1357341, 1542894, 1746747, 1970290
OFFSET
1,1
COMMENTS
Row 3 of A250561
LINKS
FORMULA
Empirical: a(n) = a(n-1) -a(n-2) +2*a(n-3) +a(n-5) -2*a(n-7) -3*a(n-9) +a(n-10) -a(n-11) +3*a(n-12) +2*a(n-14) -a(n-16) -2*a(n-18) +a(n-19) -a(n-20) +a(n-21)
also a quadratic polynomial plus a linear quasipolynomial with period 60, the first 12 being:
Empirical for n mod 60 = 0: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (23/30)*n + 1
Empirical for n mod 60 = 1: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (1853/1080)*n + (251/270)
Empirical for n mod 60 = 2: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (127/270)*n + (211/270)
Empirical for n mod 60 = 3: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (337/120)*n + (13/5)
Empirical for n mod 60 = 4: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (47/270)*n + (283/135)
Empirical for n mod 60 = 5: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2173/1080)*n + (35/54)
Empirical for n mod 60 = 6: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (23/30)*n + (13/10)
Empirical for n mod 60 = 7: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2393/1080)*n - (77/135)
Empirical for n mod 60 = 8: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (127/270)*n + (281/135)
Empirical for n mod 60 = 9: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (277/120)*n + (33/10)
Empirical for n mod 60 = 10: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (47/270)*n + (43/54)
Empirical for n mod 60 = 11: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2713/1080)*n - (7/135)
EXAMPLE
Some solutions for n=6
..2....0....5....5....4....3....2....1....1....6....5....4....5....3....2....0
..2....3....6....6....1....3....1....4....3....4....4....6....6....2....2....1
..3....5....2....6....2....3....5....4....5....3....3....4....5....2....4....0
..2....2....0....4....6....0....6....3....1....3....1....4....6....2....4....3
..0....3....1....1....3....0....5....6....3....1....0....6....3....1....4....4
CROSSREFS
Sequence in context: A082971 A374650 A176010 * A166819 A108683 A376290
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 25 2014
STATUS
approved