login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 1
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 01:26 EDT 2020. Contains 337236 sequences. (Running on oeis4.)