A251839 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row and column sum nonprime and every diagonal and antidiagonal sum prime.

981, 508, 828, 1229, 2672, 5438, 9647, 22610, 47398, 86279, 204832, 432320, 789967, 1882338, 3983708, 7285937, 17386988, 36844782, 67409449, 160977268, 341342946, 624601177, 1492090228, 3164874902, 5791630811, 13837769762, 29355806776

Offset

1,1

Comments

Column 2 of A251845.

Links

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

Formula

Empirical: a(n) = 17*a(n-3) -90*a(n-6) +191*a(n-9) -205*a(n-12) +128*a(n-15) -48*a(n-18) +8*a(n-21) for n > 26.

Example

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

Crossrefs

Cf. A251845.

Sequence in context: A109120 A128483 A056937 * A122472 A252402 A087907

Adjacent sequences: A251836 A251837 A251838 * A251840 A251841 A251842

Keyword

nonn

Author

R. H. Hardin, Dec 09 2014

Status

approved