A248536 Number of length n+3 0..7 arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth

512, 704, 992, 1412, 2000, 2960, 4424, 6644, 9968, 15356, 23648, 36380, 55856, 87680, 137072, 213500, 331424, 525044, 827144, 1296776, 2024480, 3222092, 5096048, 8016536, 12551888, 20024372, 31734104, 50006852, 78415616, 125248544

Offset

1,1

Comments

Column 7 of A248537

Links

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

Formula

Empirical: a(n) = a(n-1) +12*a(n-4) -12*a(n-5) -47*a(n-8) +47*a(n-9) +81*a(n-12) -81*a(n-13) -76*a(n-16) +76*a(n-17) +36*a(n-20) -36*a(n-21) -8*a(n-24) +8*a(n-25)

Example

Some solutions for n=6
..4....0....0....4....1....7....2....5....2....3....3....7....3....1....4....6
..4....3....3....5....2....0....0....3....6....5....6....0....1....3....7....3
..5....3....5....3....0....5....2....4....4....4....5....4....4....5....3....3
..3....6....4....4....5....4....4....4....4....4....6....5....4....3....2....4
..0....4....4....4....1....3....2....1....2....3....7....3....7....1....4....2
..4....3....7....1....2....4....0....3....6....5....6....4....5....3....3....3
..5....3....5....7....0....5....2....4....4....4....5....4....0....5....3....3
..3....6....0....4....1....0....4....4....4....0....2....1....4....3....6....0
..0....4....4....4....5....7....2....5....2....7....7....7....7....1....4....6

Crossrefs

Sequence in context: A326113 A045003 A234136 * A202461 A046311 A036333

Adjacent sequences: A248533 A248534 A248535 * A248537 A248538 A248539

Keyword

nonn

Author

R. H. Hardin, Oct 08 2014

Status

approved