A252317 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7

7815, 2579, 6011, 23422, 97191, 409636, 1741936, 7424869, 31630640, 134638865, 573240255, 2441382936, 10396958017, 44272818260, 188528191000, 802834481773, 3418801561062, 14558580766571, 61996115521347, 264004067912514

Offset

1,1

Comments

Column 4 of A252321

Links

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

Formula

Empirical: a(n) = a(n-1) +6*a(n-2) +20*a(n-3) +54*a(n-4) +38*a(n-5) -41*a(n-6) -191*a(n-7) -285*a(n-8) +297*a(n-9) +752*a(n-10) -166*a(n-11) -811*a(n-12) -153*a(n-13) +296*a(n-14) +139*a(n-15) +173*a(n-16) +339*a(n-17) -299*a(n-18) -788*a(n-19) +163*a(n-20) +779*a(n-21) +92*a(n-22) -330*a(n-23) -98*a(n-24) +18*a(n-25) -54*a(n-26) +3*a(n-27) +35*a(n-28) -3*a(n-29) +12*a(n-30) +7*a(n-31) -4*a(n-32) for n>37

Example

Some solutions for n=4
..3..3..2..3..3..3....2..3..3..3..2..3....3..3..3..3..3..3....2..3..3..2..3..3
..3..3..3..3..2..3....3..3..3..3..3..3....2..3..3..3..3..2....3..3..3..3..3..3
..3..3..3..3..3..3....3..3..3..3..3..3....3..3..3..2..3..3....3..3..3..3..2..3
..3..2..3..3..3..3....3..3..3..3..3..3....3..3..3..3..3..3....3..3..3..3..3..3
..3..3..3..2..3..3....3..3..3..2..3..3....3..3..3..3..2..3....3..3..3..2..3..3
..2..3..3..3..3..3....2..3..3..3..3..2....3..2..3..3..3..3....2..3..3..3..3..2

Crossrefs

Sequence in context: A253745 A253752 A375916 * A250026 A374576 A374507

Adjacent sequences: A252314 A252315 A252316 * A252318 A252319 A252320

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved