A251452 Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock summing to a prime.

114, 856, 6398, 47874, 358070, 2679006, 20039054, 149921686, 1121458998, 8389937086, 62760664590, 469520691478, 3512289126086, 26275557518190, 196558587418526, 1470448905636774, 11000011255301078, 82290268441602622

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 55*a(n-2) - 46*a(n-3) - 470*a(n-4) + 76*a(n-5) + 1092*a(n-6) + 432*a(n-7).

Empirical g.f.: 2*x*(57 + 314*x - 792*x^2 - 3379*x^3 + 1694*x^4 + 8880*x^5 + 3456*x^6) / (1 - 2*x - 55*x^2 + 46*x^3 + 470*x^4 - 76*x^5 - 1092*x^6 - 432*x^7). - Colin Barker, Nov 29 2018

Example

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

Crossrefs

Column 1 of A251459.

Sequence in context: A324708 A353746 A251459 * A239570 A002952 A296403

Adjacent sequences: A251449 A251450 A251451 * A251453 A251454 A251455

Keyword

nonn

Author

R. H. Hardin, Dec 02 2014

Status

approved