A268787 Number of nX6 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

20, 338, 4207, 46195, 477128, 4725018, 45515227, 429442918, 3988796543, 36591758790, 332327545513, 2993282062865, 26773510121640, 238060527618025, 2105957538309226, 18547209960131466, 162707970808249851

Offset

1,1

Comments

Column 6 of A268789.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +83*a(n-2) +210*a(n-3) -1918*a(n-4) -13444*a(n-5) -27431*a(n-6) +22868*a(n-7) +172414*a(n-8) +91292*a(n-9) -572846*a(n-10) -576908*a(n-11) +1569339*a(n-12) +1662464*a(n-13) -4129647*a(n-14) -2739590*a(n-15) +10005684*a(n-16) +128072*a(n-17) -18820309*a(n-18) +14239344*a(n-19) +18275195*a(n-20) -39512592*a(n-21) +16595129*a(n-22) +32600294*a(n-23) -63035320*a(n-24) +55225574*a(n-25) -27556538*a(n-26) +5959238*a(n-27) +1367780*a(n-28) -935764*a(n-29) -205936*a(n-30) +253428*a(n-31) -6946*a(n-32) -44268*a(n-33) +5192*a(n-34) +6896*a(n-35) -1085*a(n-36) -848*a(n-37) +74*a(n-38) +94*a(n-39) +3*a(n-40) -6*a(n-41) -a(n-42)

Example

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

Crossrefs

Cf. A268789.

Sequence in context: A084032 A166984 A167031 * A272183 A005748 A230236

Adjacent sequences: A268784 A268785 A268786 * A268788 A268789 A268790

Keyword

nonn

Author

R. H. Hardin, Feb 13 2016

Status

approved