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A247405 Number of length 1+4 0..n arrays with no disjoint pairs in any consecutive five terms having the same sum 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 20 08:20 EDT 2021. Contains 348099 sequences. (Running on oeis4.)