A252242 Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and column sum not equal to 1 3 4 6 or 7 and every 3 X 3 diagonal and antidiagonal sum equal to 1 3 4 6 or 7.

74824, 2568432, 65274264, 301990464, 10519316352, 267361717440, 1236950585856, 43087111928832, 1095113581291008, 5066549580828672, 176484810397704192, 4485585228861222912, 20752587082923540480, 722881783388494036992

Offset

1,1

Comments

Column 7 of A252243.

Links

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

Formula

Empirical: a(n) = 4104*a(n-3) - 32768*a(n-6) for n>7.

Empirical g.f.: 8*x*(9353 + 321054*x + 8159283*x^2 - 635904*x^3 - 2691072*x^4 - 65482752*x^5 + 4194304*x^6) / ((1 - 2*x)*(1 - 16*x)*(1 + 2*x + 4*x^2)*(1 + 16*x + 256*x^2)). - Colin Barker, Mar 20 2018

Example

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

Crossrefs

Cf. A252243.

Sequence in context: A104846 A206127 A230221 * A210051 A179252 A045731

Adjacent sequences: A252239 A252240 A252241 * A252243 A252244 A252245

Keyword

nonn

Author

R. H. Hardin, Dec 15 2014

Status

approved