A248437 Number of length 4+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third

2, 9, 28, 101, 198, 327, 462, 691, 932, 1203, 1474, 1829, 2184, 2551, 2954, 3459, 3964, 4501, 5038, 5653, 6286, 6925, 7564, 8327, 9114, 9907, 10712, 11577, 12442, 13363, 14284, 15307, 16342, 17383, 18454, 19609, 20764, 21925, 23098, 24389, 25680, 27009

Offset

1,1

Comments

Row 4 of A248433

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = -a(n-4) +a(n-5) +a(n-7) -a(n-8) +a(n-9) +a(n-11) -a(n-12) +a(n-13) +a(n-15) -a(n-21) -a(n-23) +a(n-24) -a(n-25) -a(n-27) +a(n-28) -a(n-29) -a(n-31) +a(n-32) +a(n-36)

Example

Some solutions for n=6
..4....1....3....1....5....3....2....6....5....4....3....2....5....3....5....1
..5....5....4....3....3....1....4....2....4....2....5....1....4....3....1....3
..6....3....2....2....1....2....0....4....6....0....1....3....6....3....3....5
..4....4....3....1....2....0....2....0....2....4....3....2....2....3....5....1
..2....2....1....0....3....4....1....2....4....2....2....4....4....3....4....3
..0....3....5....2....4....2....3....4....0....3....4....3....6....3....6....5

Crossrefs

Sequence in context: A323957 A026087 A109188 * A002532 A360023 A098518

Adjacent sequences: A248434 A248435 A248436 * A248438 A248439 A248440

Keyword

nonn

Author

R. H. Hardin, Oct 06 2014

Status

approved