A251944 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum prime and every diagonal and antidiagonal sum nonprime

2255, 1182, 1251, 2053, 3609, 7348, 14434, 29212, 60954, 125586, 260804, 550695, 1149439, 2414347, 5147608, 10837406, 22947112, 49325294, 104571648, 222836190, 482146165, 1027815785, 2201179969, 4787010362, 10247989102, 22030788568

Offset

1,1

Comments

Column 2 of A251950

Links

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

Formula

Empirical: a(n) = 20*a(n-3) -120*a(n-6) +231*a(n-9) -249*a(n-12) +198*a(n-15) -134*a(n-18) +55*a(n-21) for n>27

Example

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

Crossrefs

Sequence in context: A250160 A287701 A123297 * A077455 A068754 A222951

Adjacent sequences: A251941 A251942 A251943 * A251945 A251946 A251947

Keyword

nonn

Author

R. H. Hardin, Dec 11 2014

Status

approved