A252294 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A252294

Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 2 3 6 or 7

943, 856, 976, 1481, 2079, 3265, 5676, 10939, 21842, 45450, 94429, 201843, 436593, 950880, 2077933, 4556174, 9995748, 21960671, 48283531, 106217277, 233735492, 514456023, 1132428018, 2493020906, 5488771613, 12085003787, 26609253669

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 1 of A252295

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +a(n-2) +2*a(n-3) -3*a(n-4) -7*a(n-5) -3*a(n-6) -13*a(n-7) +10*a(n-8) +12*a(n-9) +20*a(n-10) +20*a(n-11) +18*a(n-12) +12*a(n-13) -58*a(n-14) -84*a(n-15) -26*a(n-16) +46*a(n-17) +62*a(n-18) +26*a(n-19) -28*a(n-20) -40*a(n-21) -16*a(n-22) +16*a(n-23) +24*a(n-24) +8*a(n-25) for n>30

EXAMPLE

Some solutions for n=4

..2..2..1....3..1..0....1..1..2....3..1..1....1..2..2....3..3..3....0..2..2

..1..3..1....1..0..3....2..1..1....2..0..3....3..3..2....3..3..3....1..3..1

..1..0..3....1..3..1....1..2..2....0..3..1....0..0..1....3..3..3....3..0..1

..3..2..0....2..2..1....2..2..1....2..2..0....2..1..1....2..3..3....0..1..3

..0..3..2....2..0..2....1..1..2....2..0..3....2..3..3....3..3..3....2..3..0

..1..0..3....0..2..2....2..1..1....1..2..2....0..1..0....3..3..3....3..0..2

CROSSREFS

Sequence in context: A228382 A340876 A252295 * A268268 A106431 A234485

Adjacent sequences: A252291 A252292 A252293 * A252295 A252296 A252297

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 16 2014

STATUS

approved