A270114 Number of nX4 0..7 arrays with some element plus some horizontally or vertically adjacent neighbor totalling seven exactly once.

1176, 6183744, 16972694928, 38799000374400, 81224231406183600, 161437591343857507392, 310047482243688075320784, 581128015182716709115556736, 1069573733021300551214375558640

Offset

1,1

Comments

Column 4 of A270118.

Links

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

Formula

Empirical: a(n) = 3378*a(n-1) -3070271*a(n-2) +370787212*a(n-3) -17482148143*a(n-4) +363880874050*a(n-5) -2797694462161*a(n-6) for n>7

Example

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

Crossrefs

Cf. A270118.

Sequence in context: A237774 A223340 A270147 * A258912 A237094 A321867

Adjacent sequences: A270111 A270112 A270113 * A270115 A270116 A270117

Keyword

nonn

Author

R. H. Hardin, Mar 11 2016

Status

approved