A270110 Number of n X n 0..7 arrays with some element plus some horizontally or vertically adjacent neighbor totalling seven exactly once.

0, 1344, 45440640, 38799000374400, 1043364062813432764992, 953623090124975369688224358912, 30710864722727618437291310619830386096704

Offset

1,2

Comments

Diagonal of A270118.

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Cf. A270118.

Sequence in context: A230974 A239192 A172686 * A224566 A053770 A094037

Adjacent sequences: A270107 A270108 A270109 * A270111 A270112 A270113

Keyword

nonn

Author

R. H. Hardin, Mar 11 2016

Status

approved