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

Author

R. H. Hardin Sep 20 2010

Keywords

• nonn

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)