A247405 Number of length 1+4 0..n arrays with no disjoint pairs in any consecutive five terms having the same sum

0, 40, 200, 760, 2280, 5640, 12120, 23800, 43040, 73840, 120240, 188040, 283680, 415840, 593240, 827680, 1131240, 1519200, 2007240, 2614720, 3361280, 4271080, 5368320, 6681840, 8241120, 10080760, 12235400, 14745640, 17652360, 21002520

Offset

1,2

Comments

Row 1 of A247404

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +a(n-4) -2*a(n-5) +4*a(n-6) -2*a(n-7) +a(n-8) -a(n-9) -2*a(n-10) +3*a(n-11) -a(n-12)

Empirical for n mod 12 = 0: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n

Empirical for n mod 12 = 1: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 20

Empirical for n mod 12 = 2: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n + 40

Empirical for n mod 12 = 3: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 80

Empirical for n mod 12 = 4: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n

Empirical for n mod 12 = 5: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 60

Empirical for n mod 12 = 6: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n

Empirical for n mod 12 = 7: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 80

Empirical for n mod 12 = 8: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n + 40

Empirical for n mod 12 = 9: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 20

Empirical for n mod 12 = 10: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 34*n

Empirical for n mod 12 = 11: a(n) = n^5 - 5*n^4 + 30*n^3 - 65*n^2 + 19*n + 120

Example

Some solutions for n=6
..2....6....3....2....0....0....6....0....5....6....5....4....4....6....5....1
..4....2....0....0....5....5....6....5....6....6....4....4....2....2....0....0
..1....1....6....5....6....6....1....6....3....3....4....1....6....6....6....6
..1....6....6....4....0....3....6....0....5....5....0....4....1....1....2....0
..1....3....6....0....2....6....0....3....1....6....4....5....1....0....5....3

Crossrefs

Sequence in context: A187510 A187379 A077818 * A235270 A181637 A111176

Adjacent sequences: A247402 A247403 A247404 * A247406 A247407 A247408

Keyword

nonn

Author

R. H. Hardin, Sep 16 2014

Status

approved