A252277 - OEIS

A252277

Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 2 3 4 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 2 3 4 6 or 7

1260, 7922, 37160, 85808, 518498, 2489352, 5767680, 34496526, 165959340, 384876232, 2298587370, 11061103280, 25655550076, 153191338398, 737201742464, 1709930351560, 10209850851410, 49133026339596, 113963788270572

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

OFFSET

1,1

COMMENTS

Column 7 of A252278

LINKS

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

FORMULA

Empirical: a(n) = 86*a(n-3) -1415*a(n-6) +8680*a(n-9) -22666*a(n-12) +28036*a(n-15) -15888*a(n-18) +3168*a(n-21) for n>27

EXAMPLE

Some solutions for n=4

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

..2..1..2..2..1..2..2..1..2....2..1..2..2..1..2..2..1..2

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

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

..2..1..2..2..1..2..2..1..2....2..1..2..2..1..2..2..1..2

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

CROSSREFS

Sequence in context: A179690 A350039 A158737 * A203402 A047634 A172314

Adjacent sequences: A252274 A252275 A252276 * A252278 A252279 A252280

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 16 2014

STATUS

approved