A252147 Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 7

44707, 11573, 21375, 17166, 44234, 34320, 108750, 78781, 254289, 178690, 631331, 408458, 1557034, 972865, 3894549, 2351136, 9859334, 5724828, 25112827, 14226925, 64213200, 35652840, 165276046, 89908958, 426691518, 229088911, 1104127770

Offset

1,1

Comments

Column 7 of A252148

Links

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

Formula

Empirical: a(n) = 3*a(n-2) +3*a(n-3) +a(n-4) -9*a(n-5) -2*a(n-6) -3*a(n-7) -6*a(n-8) +3*a(n-9) -8*a(n-10) +27*a(n-11) +3*a(n-12) +27*a(n-13) +2*a(n-14) -12*a(n-15) -33*a(n-17) +a(n-18) -27*a(n-19) +6*a(n-20) +9*a(n-21) +8*a(n-22) +15*a(n-23) -2*a(n-24) +3*a(n-25) -5*a(n-26) -3*a(n-27) -a(n-28) +a(n-30) for n>40

Example

Some solutions for n=4
..1..3..1..3..1..3..1..2..0....2..3..2..0..3..0..3..0..2
..3..0..3..0..3..0..3..0..2....1..3..1..3..1..3..1..3..1
..1..3..1..3..1..3..1..3..3....3..0..3..0..3..0..3..0..3
..3..0..3..0..3..0..3..0..2....1..3..1..3..1..3..1..3..1
..1..3..1..3..1..3..1..3..1....3..0..3..0..3..0..3..0..2
..3..0..3..0..3..0..3..0..2....3..2..1..3..1..2..3..2..0

Crossrefs

Sequence in context: A206380 A204786 A248066 * A225814 A209909 A251790

Adjacent sequences: A252144 A252145 A252146 * A252148 A252149 A252150

Keyword

nonn

Author

R. H. Hardin, Dec 14 2014

Status

approved