A202513 - OEIS

A202513

Number of zero-sum -n..n arrays of 5 elements with first through third differences also in -n..n

5, 21, 95, 239, 529, 1041, 1785, 3009, 4655, 6937, 10007, 13823, 18963, 25151, 32837, 42225, 53147, 66679, 82163, 100347, 121523, 145299, 173373, 204621, 240115, 280223, 324311, 374807, 429953, 491279, 559193, 632717, 715225, 804133, 901479

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OFFSET

1,1

COMMENTS

Row 5 of A202511

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..175

FORMULA

Empirical: a(n) = -a(n-1) -a(n-2) +3*a(n-5) +3*a(n-6) +3*a(n-7) +a(n-9) -2*a(n-10) -a(n-11) -2*a(n-12) +a(n-13) -3*a(n-14) -2*a(n-15) -5*a(n-16) -2*a(n-17) -3*a(n-18) +3*a(n-19) +2*a(n-20) +5*a(n-21) +2*a(n-22) +3*a(n-23) -a(n-24) +2*a(n-25) +a(n-26) +2*a(n-27) -a(n-28) -3*a(n-30) -3*a(n-31) -3*a(n-32) +a(n-35) +a(n-36) +a(n-37)

EXAMPLE

Some solutions for n=7

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

.-3...-2...-2...-1...-4....0...-1...-1...-3...-3....0...-2...-2...-3...-3....1

.-4...-1....2...-4...-2...-3....3....1....1....1...-2...-4...-2...-1....0....4

..0...-1....3...-1....1...-2....3....2....3....5...-3...-1....1....0....2....2

..6....5....2....5....7....2....1....0....3....2....1....3....5....5....5...-3

CROSSREFS

Sequence in context: A273570 A103519 A178876 * A361775 A343349 A159289

Adjacent sequences: A202510 A202511 A202512 * A202514 A202515 A202516

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 20 2011

STATUS

approved