A223295 4-loop graph coloring a rectangular array: number of nX6 0..8 arrays where 0..8 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 0,7 7,8 8,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph

3360, 773928, 377262504, 195340203144, 101979342907800, 53263771547091072, 27821347292299780344, 14532016431709183293744, 7590559695644291402339736, 3964804074342648939947790744, 2070950237042448767464370199792

Offset

1,1

Comments

Column 6 of A223297

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 545*a(n-1) -9509*a(n-2) -1272418*a(n-3) +28188249*a(n-4) +343455921*a(n-5) -10615698560*a(n-6) +6644919388*a(n-7) +1115143980458*a(n-8) -4865200389068*a(n-9) -36863182740867*a(n-10) +243871158760989*a(n-11) +348237766702019*a(n-12) -4347692324962003*a(n-13) +1676659396161043*a(n-14) +32771062182083492*a(n-15) -39962029771741368*a(n-16) -99930101839316382*a(n-17) +187463467710652368*a(n-18) +68152359684322692*a(n-19) -275965060596418260*a(n-20) +88177492440040032*a(n-21) +73781671207252608*a(n-22) -31124995946138304*a(n-23) -1497321395510976*a(n-24) for n>25

Example

Some solutions for n=3
..1..0..3..0..2..0....1..0..2..0..1..0....1..0..1..0..5..0....1..0..2..0..1..0
..0..1..0..6..0..8....0..1..0..7..0..1....0..1..0..8..0..7....0..1..0..1..0..8
..1..0..3..0..3..0....1..0..7..0..6..0....1..0..1..0..7..8....1..0..6..0..1..0

Crossrefs

Sequence in context: A159000 A032773 A323965 * A115488 A020434 A061334

Adjacent sequences: A223292 A223293 A223294 * A223296 A223297 A223298

Keyword

nonn

Author

R. H. Hardin Mar 19 2013

Status

approved