A248533 Number of length n+3 0..4 arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth.

101, 113, 125, 137, 149, 173, 197, 221, 245, 293, 341, 389, 437, 533, 629, 725, 821, 1013, 1205, 1397, 1589, 1973, 2357, 2741, 3125, 3893, 4661, 5429, 6197, 7733, 9269, 10805, 12341, 15413, 18485, 21557, 24629, 30773, 36917, 43061, 49205, 61493, 73781

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 2*a(n-4) - 2*a(n-5).

Empirical g.f.: x*(101 + 12*x + 12*x^2 + 12*x^3 - 190*x^4) / ((1 - x)*(1 - 2*x^4)). - Colin Barker, Nov 08 2018

Example

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

Crossrefs

Column 4 of A248537.

Sequence in context: A352439 A214527 A084413 * A069691 A084414 A164937

Adjacent sequences: A248530 A248531 A248532 * A248534 A248535 A248536

Keyword

nonn

Author

R. H. Hardin, Oct 08 2014

Status

approved