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 A223365 6X6X6 triangular graph coloring a rectangular array: number of nX3 0..20 arrays where 0..20 label nodes of the fully triangulated graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph 1
 420, 11610, 357354, 11206806, 356391222, 11391019146, 365447949798, 11741128578822, 377630573527206, 12150390210921654, 391071237626540478, 12588165595068116826, 405241143066881319750, 13045880634316557698334 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A223370 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 23*a(n-1) +897*a(n-2) -15543*a(n-3) -239874*a(n-4) +3284289*a(n-5) +27049393*a(n-6) -330039039*a(n-7) -1521495660*a(n-8) +18314438985*a(n-9) +47878976407*a(n-10) -618252955256*a(n-11) -889060713666*a(n-12) +13552173820568*a(n-13) +9580003346768*a(n-14) -201847740643953*a(n-15) -46867751747346*a(n-16) +2108268911742322*a(n-17) -184187510050618*a(n-18) -15779764589198623*a(n-19) +4879627711864385*a(n-20) +85835278187584234*a(n-21) -40138511702965646*a(n-22) -342053440022551516*a(n-23) +199639474840833405*a(n-24) +1001161151524243334*a(n-25) -671464975697570928*a(n-26) -2146406246471550814*a(n-27) +1582756069996035189*a(n-28) +3342452561011804599*a(n-29) -2639262830436925013*a(n-30) -3723873632097428362*a(n-31) +3096692775113977724*a(n-32) +2897671400594634762*a(n-33) -2511627603739201088*a(n-34) -1516552491534508238*a(n-35) +1362811032192743844*a(n-36) +502215369425262432*a(n-37) -467555871709031156*a(n-38) -94719302460861132*a(n-39) +91628605259689448*a(n-40) +8417956616498704*a(n-41) -8338690645967040*a(n-42) -301027284753856*a(n-43) +203944076489856*a(n-44) +12153311182848*a(n-45) +24038117888*a(n-46) EXAMPLE Some solutions for n=3 .12..8.13....2..1..2....4..7.12....4..7.12....4..7.11....4..8..9....4..3..4 ..8.12..8....5..4..1....3..4..8....3..4..8....1..4..7....8..4..5....7..4..5 .12.11.12....8..5..2....4..8.13....4..3..4....2..1..3....7..8..4....4..1..2 Vertex neighbors: 0 -> 1 2 1 -> 0 2 3 4 2 -> 0 1 4 5 3 -> 1 4 6 7 4 -> 1 2 3 5 7 8 5 -> 2 4 8 9 6 -> 3 7 10 11 7 -> 3 4 6 8 11 12 8 -> 4 5 7 9 12 13 9 -> 5 8 13 14 10 -> 6 11 15 16 11 -> 6 7 10 12 16 17 12 -> 7 8 11 13 17 18 13 -> 8 9 12 14 18 19 14 -> 9 13 19 20 15 -> 10 16 16 -> 10 11 15 17 17 -> 11 12 16 18 18 -> 12 13 17 19 19 -> 13 14 18 20 20 -> 14 19 CROSSREFS Sequence in context: A317983 A179718 A166784 * A288071 A289226 A133712 Adjacent sequences:  A223362 A223363 A223364 * A223366 A223367 A223368 KEYWORD nonn AUTHOR R. H. Hardin Mar 19 2013 STATUS approved

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Last modified December 2 16:17 EST 2021. Contains 349445 sequences. (Running on oeis4.)