A183341 Number of nX9 binary arrays with each 1 adjacent to exactly one 1 vertically and one 1 horizontally

1, 28, 109, 380, 2450, 12075, 55471, 286079, 1429824, 6989477, 34856362, 173451524, 858586095, 4263159553, 21172762001, 105041615196, 521348098233, 2587930504660, 12843811121650, 63746482751185, 316398514788731

Offset

1,2

Comments

Equivalent to all 1s connected only in 2X2 blocks

Column 9 of A183342

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=a(n-1)+4*a(n-2)+66*a(n-3)+95*a(n-4)+43*a(n-5)-720*a(n-6)-1911*a(n-7)-1442*a(n-8)+3264*a(n-9)+10821*a(n-10)+19141*a(n-11)+2814*a(n-12)-66628*a(n-13)-89804*a(n-14)+31181*a(n-15)+153550*a(n-16)+92838*a(n-17)+40230*a(n-18)-70110*a(n-19)-229684*a(n-20)-107631*a(n-21)-94711*a(n-22)+28881*a(n-23)+390574*a(n-24)+124645*a(n-25)-26599*a(n-26)-25097*a(n-27)-277598*a(n-28)+259486*a(n-29)+159878*a(n-30)-12870*a(n-31)-21470*a(n-32)-444709*a(n-33)-78037*a(n-34)-123573*a(n-35)+71536*a(n-36)+64021*a(n-37)-594*a(n-38)+19314*a(n-39)-12660*a(n-40)+3610*a(n-41)+920*a(n-42)-1448*a(n-43)+704*a(n-44)-128*a(n-45)

Example

Some solutions for 5X9
..0..0..0..0..1..1..0..1..1....0..0..0..0..1..1..0..0..0
..0..0..0..0..1..1..0..1..1....1..1..0..0..1..1..0..0..0
..0..0..0..0..0..0..0..0..0....1..1..0..0..0..0..0..1..1
..1..1..0..0..1..1..0..0..0....0..0..0..1..1..0..0..1..1
..1..1..0..0..1..1..0..0..0....0..0..0..1..1..0..0..0..0

Crossrefs

Sequence in context: A068196 A044279 A044660 * A118613 A245153 A295981

Adjacent sequences: A183338 A183339 A183340 * A183342 A183343 A183344

Keyword

nonn

Author

R. H. Hardin Jan 04 2011

Status

approved