A270146 Number of nX3 0..7 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling seven exactly once.

112, 85056, 24250368, 5750902944, 1246566350496, 256330155581328, 50909823129746016, 9865341820791957984, 1876922088531822540288, 352046674014022502244432, 65286683791880565255135360

Offset

1,1

Comments

Column 3 of A270150.

Links

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

Formula

Empirical: a(n) = 344*a(n-1) -31000*a(n-2) +235620*a(n-3) +897074*a(n-4) -11474284*a(n-5) +9154676*a(n-6) +131736204*a(n-7) -307742569*a(n-8) +77937860*a(n-9) -5244100*a(n-10) for n>11

Example

Some solutions for n=2
..0..5..6. .6..0..2. .1..1..5. .3..0..7. .7..4..4. .7..6..4. .7..5..0
..6..3..4. .2..7..2. .3..5..6. .2..6..6. .0..6..7. .7..6..3. .1..2..1

Crossrefs

Cf. A270150.

Sequence in context: A362963 A304394 A210292 * A184898 A270113 A275052

Adjacent sequences: A270143 A270144 A270145 * A270147 A270148 A270149

Keyword

nonn

Author

R. H. Hardin, Mar 12 2016

Status

approved