A251838 Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum nonprime and every diagonal and antidiagonal sum prime

974, 981, 641, 872, 1443, 1951, 2784, 4949, 7897, 11384, 21033, 35203, 50846, 95287, 161329, 232978, 438821, 745265, 1075374, 2030079, 3451785, 4975148, 9405623, 16003305, 23037002, 43604345, 74229499, 106714968, 202216349, 344400871

Offset

1,1

Comments

Column 1 of A251845

Links

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

Formula

Empirical: a(n) = 13*a(n-3) +a(n-5) -62*a(n-6) -12*a(n-8) +140*a(n-9) +50*a(n-11) -175*a(n-12) -90*a(n-14) +127*a(n-15) +85*a(n-17) -50*a(n-18) -42*a(n-20) +8*a(n-21) +8*a(n-23) for n>28

Example

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

Crossrefs

Sequence in context: A232409 A275060 A251837 * A251845 A254072 A253363

Adjacent sequences: A251835 A251836 A251837 * A251839 A251840 A251841

Keyword

nonn

Author

R. H. Hardin, Dec 09 2014

Status

approved