A200167 Number of -n..n arrays x(0..3) of 4 elements with nonzero sum and with zero through 3 differences all nonzero.

0, 76, 576, 2256, 6160, 13888, 27160, 48380, 80096, 125412, 187552, 270688, 378512, 515980, 687836, 899548, 1156496, 1465440, 1832040, 2263800, 2767676, 3351476, 4022752, 4790848, 5663388, 6650440, 7761148, 9005676, 10393744, 11937276

Offset

1,2

Comments

Row 4 of A200165.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-2) +2*a(n-3) -a(n-4) -3*a(n-5) -a(n-6) +a(n-9) +3*a(n-10) +a(n-11) -2*a(n-12) -2*a(n-13) +a(n-15).

Example

Some solutions for n=5
.-1...-5...-1...-3....3...-4...-1....3...-4....3....5...-2...-5...-4....5....1
..4....4....5....4...-2....4....3...-4....5....1...-1...-5...-2...-3...-3....5
..1....5...-2....2....2...-5....4...-1....1....3....1...-1....2....4...-2....2
..3....4....4...-2....1....1...-5....5....4...-4....5....1...-3....5...-5...-2

Crossrefs

Cf. A200165.

Sequence in context: A262790 A184680 A129626 * A178262 A253411 A185481

Adjacent sequences: A200164 A200165 A200166 * A200168 A200169 A200170

Keyword

nonn

Author

R. H. Hardin, Nov 13 2011

Status

approved