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
Keywords
Examples
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
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)
Comments