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A248491 Number of length 2+5 0..n arrays with some three disjoint pairs in each consecutive six terms having the same sum. 1
22, 183, 844, 2605, 6306, 13147, 24208, 40449, 64030, 96391, 139212, 195013, 265714, 353595, 462136, 593137, 749598, 935839, 1154140, 1407621, 1701562, 2038603, 2422584, 2859145, 3351406, 3903807, 4522948, 5211829, 5975610, 6821731, 7753672 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

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

Empirical for n mod 12 = 0: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + 1

Empirical for n mod 12 = 1: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n - (17/18)

Empirical for n mod 12 = 2: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + (193/3)*n + (1009/9)

Empirical for n mod 12 = 3: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + (167/2)

Empirical for n mod 12 = 4: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + (329/9)

Empirical for n mod 12 = 5: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + (193/3)*n + (1343/18)

Empirical for n mod 12 = 6: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + 1

Empirical for n mod 12 = 7: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + (2143/18)

Empirical for n mod 12 = 8: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + (193/3)*n + (1009/9)

Empirical for n mod 12 = 9: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n - (73/2)

Empirical for n mod 12 = 10: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + 91*n + (329/9)

Empirical for n mod 12 = 11: a(n) = (15/2)*n^4 + (280/9)*n^3 - (320/3)*n^2 + (193/3)*n + (3503/18).

Empirical g.f.: x*(22 + 139*x + 500*x^2 + 1056*x^3 + 1640*x^4 + 2001*x^5 + 1542*x^6 + 383*x^7 - 102*x^8 - 700*x^9 - 2*x^10 + x^11) / ((1 - x)^5*(1 + x)*(1 + x^2)*(1 + x + x^2)^2). - Colin Barker, Nov 08 2018

EXAMPLE

Some solutions for n=6:

..6....3....3....0....4....4....0....4....5....4....5....5....1....5....4....6

..2....4....5....3....2....5....4....2....3....6....2....5....3....0....5....0

..4....1....4....1....5....3....6....3....3....2....1....6....3....2....2....6

..0....6....3....5....2....4....2....2....1....2....3....1....5....4....3....0

..6....5....4....3....1....2....6....1....0....6....6....0....4....1....6....3

..0....2....2....6....4....6....0....3....6....4....4....1....2....3....4....3

..6....3....3....0....4....4....0....4....5....4....5....5....4....5....1....6

CROSSREFS

Row 2 of A248489.

Sequence in context: A248489 A248490 A191012 * A248492 A248493 A248494

Adjacent sequences:  A248488 A248489 A248490 * A248492 A248493 A248494

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 07 2014

STATUS

approved

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Last modified October 17 00:35 EDT 2021. Contains 348048 sequences. (Running on oeis4.)