A239034 Number of 7Xn 0..2 arrays with no element equal to the sum of elements to its left or one plus the sum of the elements above it, modulo 3.

8, 64, 428, 2195, 9319, 33699, 107611, 311585, 833304, 2086074, 4936712, 11126665, 24022753, 49913047, 100179401, 194844297, 368222528, 677728244, 1217319704, 2137637135, 3675638019, 6197499195, 10259782783, 16695406105, 26732874536

Offset

1,1

Comments

Row 7 of A239030

Links

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

Formula

Empirical: a(n) = (1/1036800)*n^12 - (1961/39916800)*n^11 + (13339/7257600)*n^10 - (30521/725760)*n^9 + (583409/806400)*n^8 - (400873/44800)*n^7 + (86137751/1036800)*n^6 - (407381983/725760)*n^5 + (4957467353/1814400)*n^4 - (8367100109/907200)*n^3 + (515324983/25200)*n^2 - (185067023/6930)*n + 15601 for n>3

Example

Some solutions for n=5
..2..0..0..0..0....2..0..0..0..0....2..0..0..0..0....2..0..0..0..0
..2..0..0..0..0....1..2..2..0..0....1..2..2..0..0....2..0..0..0..0
..1..0..0..2..2....2..1..1..2..2....2..1..1..2..2....1..2..2..0..0
..2..0..0..1..2....1..0..0..2..2....1..2..2..1..2....2..1..1..2..2
..1..0..2..2..0....2..0..0..1..1....2..1..1..0..0....1..2..2..1..1
..1..0..2..1..0....2..0..0..1..1....2..0..0..0..0....1..2..2..0..0
..2..0..1..2..0....1..0..0..0..0....1..2..2..0..1....2..0..1..2..0

Crossrefs

Sequence in context: A181214 A283859 A222446 * A213296 A223564 A146885

Adjacent sequences: A239031 A239032 A239033 * A239035 A239036 A239037

Keyword

nonn

Author

R. H. Hardin, Mar 09 2014

Status

approved