A180754 Half the number of nX5 binary arrays with each element equal to at least two neighbors

0, 3, 3, 21, 86, 410, 1874, 8840, 41755, 197883, 936625, 4434387, 20996674, 99434998, 470911050, 2230166446, 10561720749, 50018822099, 236882697591, 1121846953883, 5312927519916, 25161362888858, 119161085234850, 564332106834338

Offset

1,2

Comments

Column 5 of A180760

Links

R. H. Hardin, Table of n, a(n) for n=1..99

Formula

Empirical: a(n) = 9*a(n-1) - 26*a(n-2) + 24*a(n-3) + 47*a(n-4) - 157*a(n-5) - 43*a(n-6) + 641*a(n-7) - 643*a(n-8) - 952*a(n-9) + 3460*a(n-10) - 2021*a(n-11) - 2111*a(n-12) + 2715*a(n-13) - 1249*a(n-14) - 4657*a(n-15) - 1514*a(n-16) + 1961*a(n-17) - 1230*a(n-18) + 6713*a(n-19) + 8832*a(n-20) + 10212*a(n-21) + 1971*a(n-22) - 6552*a(n-23) - 2819*a(n-24) - 2898*a(n-25) - 973*a(n-26) + 302*a(n-27) + 433*a(n-28) + 286*a(n-29)

Crossrefs

Sequence in context: A209528 A369751 A214778 * A224091 A224751 A368766

Adjacent sequences: A180751 A180752 A180753 * A180755 A180756 A180757

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved