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A223462 6X6X6 triangular graph without horizontal edges coloring a rectangular array: number of nX3 0..20 arrays where 0..20 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 6,10 6,11 7,11 7,12 8,12 8,13 9,13 9,14 10,15 10,16 11,16 11,17 12,17 12,18 13,18 13,19 14,19 14,20 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph 1
190, 2840, 47100, 789796, 13504044, 231085748, 3988872656, 68744309868, 1190949680204, 20584337901440, 357143742858616, 6180644127657520, 107304034484773564, 1858033330929059492, 32266796953842297480 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 3 of A223467
LINKS
FORMULA
Empirical: a(n) = 751*a(n-2) -213977*a(n-4) +30621250*a(n-6) -2460992507*a(n-8) +119254462102*a(n-10) -3670996485078*a(n-12) +75009157476789*a(n-14) -1056588922332331*a(n-16) +10576074147463216*a(n-18) -76959427833100718*a(n-20) +413739436651265546*a(n-22) -1660689308745581771*a(n-24) +5005542176662370394*a(n-26) -11348860916160032402*a(n-28) +19319641870299497561*a(n-30) -24574099114255799068*a(n-32) +23182072953460411397*a(n-34) -16063563012586221221*a(n-36) +8081476839997677366*a(n-38) -2910695207618822958*a(n-40) +737493263291407444*a(n-42) -128540692908762460*a(n-44) +14965848663295632*a(n-46) -1117954806914792*a(n-48) +50415617089984*a(n-50) -1228263380544*a(n-52) +12208371840*a(n-54) for n>55
EXAMPLE
Some solutions for n=3
.17.12..7....6.11.17....4..1..0....2..5..8....4..2..5....5..8.13...11..6.10
.11..7..3...11..7.11....2..4..1....0..2..4....8..4..8....8.12..8....6.10..6
..7..3..1...17.11..7....4..1..3....1..0..1....5..2..4....5..8..5...10.16.10
CROSSREFS
Sequence in context: A258725 A232387 A296521 * A184192 A263523 A133241
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 20 2013
STATUS
approved

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Last modified March 29 11:14 EDT 2024. Contains 371278 sequences. (Running on oeis4.)