A180764 Half the number of nX4 binary arrays with each element equal to at least one neighbor

2, 34, 390, 4475, 52186, 606546, 7053923, 82032712, 953982820, 11094190209, 129018028226, 1500393683522, 17448578663219, 202915341402216, 2359770191311572, 27442554696574793, 319138622503858354

Offset

1,1

Comments

Column 4 of A180771

Links

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

Formula

Empirical: a(n) = 9*a(n-1) + 35*a(n-2) - 29*a(n-3) - 256*a(n-4) - 120*a(n-5) + 695*a(n-6) + 579*a(n-7) - 949*a(n-8) - 1076*a(n-9) + 485*a(n-10) + 1488*a(n-11) + 588*a(n-12) - 857*a(n-13) - 368*a(n-14) - 73*a(n-15) - 52*a(n-16) + 26*a(n-17) + 14*a(n-18) + 12*a(n-19) - 4*a(n-20)

Crossrefs

Sequence in context: A301611 A224294 A092408 * A228654 A005261 A104898

Adjacent sequences: A180761 A180762 A180763 * A180765 A180766 A180767

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved