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A248490 Number of length 1+5 0..n arrays with some three disjoint pairs in each consecutive six terms having the same sum. 1
22, 183, 724, 2125, 4986, 10147, 18568, 31449, 50110, 76111, 111132, 157093, 216034, 290235, 382096, 494257, 629478, 790759, 981220, 1204221, 1463242, 1762003, 2104344, 2494345, 2936206, 3434367, 3993388, 4618069, 5313330, 6084331, 6936352 (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) = 4*a(n-1) - 5*a(n-2) + 5*a(n-4) - 4*a(n-5) + a(n-6).

Empirical for n mod 2 = 0: a(n) = (15/2)*n^4 + 10*n^2 + 11*n + 1.

Empirical for n mod 2 = 1: a(n) = (15/2)*n^4 + 10*n^2 + 11*n - (13/2).

Empirical g.f.: x*(22 + 95*x + 102*x^2 + 144*x^3 - 4*x^4 + x^5) / ((1 - x)^5*(1 + x)). - Colin Barker, Nov 08 2018

EXAMPLE

Some solutions for n=6:

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

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

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

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

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

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

CROSSREFS

Row 1 of A248489.

Sequence in context: A197496 A107969 A248489 * A191012 A248491 A248492

Adjacent sequences:  A248487 A248488 A248489 * A248491 A248492 A248493

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 07 2014

STATUS

approved

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Last modified October 23 08:40 EDT 2021. Contains 348211 sequences. (Running on oeis4.)