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