A184061 T(n,k) = Number of strings of n+2 numbers x(i) in -k..k with the sum of x(i) equal to zero and the sums of x(i)*x(i+1) and x(i)*x(i+2) equal to each other.

1, 1, 3, 1, 9, 11, 1, 11, 31, 21, 1, 19, 65, 107, 61, 1, 25, 109, 243, 501, 179, 1, 31, 143, 541, 1731, 2339, 447, 1, 33, 207, 839, 4769, 11251, 10303, 1243, 1, 41, 245, 1531, 10135, 40483, 67083, 44523, 3359, 1, 43, 337, 2145, 21411, 106047, 327223, 426379

Offset

1,3

Comments

Table starts

....1......1........1........1.......1.......1......1......1.....1....1...1..1

....3......9.......11.......19......25......31.....33.....41....43...53..59.75

...11.....31.......65......109.....143.....207....245....337...427..491.573

...21....107......243......541.....839....1531...2145...3345..4477.6181

...61....501.....1731.....4769...10135...21411..35451..59353.89619

..179...2339....11251....40483..106047..251231.496519.945243

..447..10303....67083...327223.1015445.2880959

.1243..44523...426379..2590527.9974135

.3359.198695..2719451.20896283

.9465.888601.17387313

Links

R. H. Hardin, Table of n, a(n) for n = 1..84

Example

Some solutions for n=5, k=4
..3....3....1....1...-1....2....3....0....1....1...-2...-1...-1...-2....1....2
..1...-2....0...-4...-2....1....0...-1...-4....0...-2....0...-2...-2...-2....3
.-4...-4...-4....0...-4...-2...-2....2...-1....2...-3....2....0...-1...-1...-1
..2....2....1...-2....4...-4....1....4....1....0....2....1....0....0....1....4
.-1....1....0....0....1....2...-4...-2...-1....1...-1....0....1....2...-1...-2
.-3....4....1....3....2...-1....0....0....3....0....3...-4....0....0....1...-3
..2...-4....1....2....0....2....2...-3....1...-4....3....2....2....3....1...-3

Crossrefs

Sequence in context: A163394 A225469 A095069 * A222057 A260285 A242499

Adjacent sequences: A184058 A184059 A184060 * A184062 A184063 A184064

Keyword

nonn,tabl

Author

R. H. Hardin, Jan 09 2011

Status

approved