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A247536 Number of length 4+3 0..n arrays with some disjoint pairs in every consecutive four terms having the same sum 1
8, 81, 364, 1007, 2164, 3997, 6584, 10219, 14852, 20847, 28108, 37095, 47564, 60087, 74428, 91101, 109760, 131243, 154956, 181677, 211024, 243709, 279136, 318445, 360676, 406933, 456648, 510683, 568172, 630613, 696744, 767859, 843244, 923955 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A247533

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..349

FORMULA

Empirical: a(n) = -a(n-1) -a(n-2) +a(n-4) +2*a(n-5) +3*a(n-6) +3*a(n-7) +2*a(n-8) -2*a(n-10) -4*a(n-11) -4*a(n-12) -4*a(n-13) -2*a(n-14) +2*a(n-16) +3*a(n-17) +3*a(n-18) +2*a(n-19) +a(n-20) -a(n-22) -a(n-23) -a(n-24)

Also as a cubic plus a linear quasipolynomial with period 420, first 12 listed:

Empirical for n mod 420 = 0: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (4243/210)*n + 1

Empirical for n mod 420 = 1: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (2003/210)*n + (622/45)

Empirical for n mod 420 = 2: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (3263/210)*n + (3998/315)

Empirical for n mod 420 = 3: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (2003/210)*n + (148/5)

Empirical for n mod 420 = 4: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (4243/210)*n - (3821/315)

Empirical for n mod 420 = 5: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (341/70)*n + (3580/63)

Empirical for n mod 420 = 6: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (4243/210)*n - (404/35)

Empirical for n mod 420 = 7: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (2003/210)*n + (784/45)

Empirical for n mod 420 = 8: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (3263/210)*n + (1187/45)

Empirical for n mod 420 = 9: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (2003/210)*n + (886/35)

Empirical for n mod 420 = 10: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (4243/210)*n - (184/9)

Empirical for n mod 420 = 11: a(n) = (15541/630)*n^3 - (1401/35)*n^2 + (341/70)*n + (20294/315)

EXAMPLE

Some solutions for n=6

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A303184 A302325 A303018 * A302822 A303515 A027768

Adjacent sequences:  A247533 A247534 A247535 * A247537 A247538 A247539

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 18 2014

STATUS

approved

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Last modified October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)