A198714 Number of nX7 0..3 arrays with values 0..3 introduced in row major order and no element equal to any horizontal or vertical neighbor

122, 58825, 28609241, 13925032958, 6778819400772, 3300094936852775, 1606578861528554441, 782129027546108478208, 380763168247444298026697, 185366606445710896112671190, 90241867886483759053800200221

Offset

1,1

Comments

Column 7 of A198715

Links

R. H. Hardin, Table of n, a(n) for n = 1..126

Formula

Empirical: a(n) = 820*a(n-1) -205689*a(n-2) +23977335*a(n-3) -1448890080*a(n-4) +40681354716*a(n-5) +113470351405*a(n-6) -45083135350759*a(n-7) +1384281526165416*a(n-8) -16268081626571563*a(n-9) -63890727017432669*a(n-10) +4141584863538946248*a(n-11) -41819886892303325457*a(n-12) -30483804619910407683*a(n-13) +3863177257558021068078*a(n-14) -27574675558592643871665*a(n-15) -5974253069771812381395*a(n-16) +994204560645628682891988*a(n-17) -4133294712546191129276631*a(n-18) -5200219344858789634094007*a(n-19) +79782056692975632581941806*a(n-20) -145976694071885459756226729*a(n-21) -381423099164490179830401489*a(n-22) +1687752294947845021038392100*a(n-23) -947863788801858331624770840*a(n-24) -4416578720165084280803867511*a(n-25) +7519754083669273956859949007*a(n-26) -393515001351016977961508328*a(n-27) -8318760918675594342013626309*a(n-28) +7729370069736269915861360652*a(n-29) -2679235928159828068047490236*a(n-30) +224133015493782945421410924*a(n-31) +60130490872795258151715444*a(n-32) -9198797534128825159826898*a(n-33)

Example

Some solutions with all values from 0 to 3 for n=4
..0..1..0..2..0..1..2....0..1..0..2..0..3..0....0..1..0..2..1..3..1
..1..0..2..0..2..3..1....1..0..2..0..2..1..3....1..0..2..0..3..1..0
..0..1..0..2..1..2..0....0..1..0..2..0..3..1....0..1..0..2..1..0..3
..1..0..2..0..3..1..2....1..0..2..0..3..0..3....1..0..2..0..2..3..1

Crossrefs

Sequence in context: A209105 A223131 A208256 * A199653 A241112 A240705

Adjacent sequences: A198711 A198712 A198713 * A198715 A198716 A198717

Keyword

nonn

Author

R. H. Hardin Oct 29 2011

Status

approved