A222837 Number of nX7 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order

163, 6144, 5832, 10584, 22848, 55296, 138240, 301056, 642048, 1382400, 3022848, 6690816, 14816256, 32741376, 72244224, 159258624, 351111168, 774297600, 1707764736, 3766818816, 8308300800, 18324658176, 40416165888, 89140107264

Offset

1,1

Comments

Column 7 of A222838

Links

R. H. Hardin, Table of n, a(n) for n = 1..64

Formula

Empirical: a(n) = 2*a(n-1) +a(n-3) -2*a(n-4) +4*a(n-5) +a(n-6) -a(n-9) for n>14

Example

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

Crossrefs

Sequence in context: A305723 A232260 A027543 * A134160 A219127 A270203

Adjacent sequences: A222834 A222835 A222836 * A222838 A222839 A222840

Keyword

nonn

Author

R. H. Hardin Mar 06 2013

Status

approved