A223695 - OEIS

A223695

Petersen graph (8,2) coloring a rectangular array: number of 4Xn 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph

65536, 34992, 595584, 10817856, 223096320, 4777430544, 105181093728, 2349947152944, 52986541817952, 1201648395980448, 27349053878517120, 623834583118758144, 14249136041512493184, 325740124104297732288

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Row 4 of A223692

LINKS

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

FORMULA

Empirical: a(n) = 25*a(n-1) +166*a(n-2) -4762*a(n-3) -15242*a(n-4) +261578*a(n-5) +557344*a(n-6) -5966572*a(n-7) -10691953*a(n-8) +66155465*a(n-9) +113681634*a(n-10) -380763790*a(n-11) -672252588*a(n-12) +1143346268*a(n-13) +2171718000*a(n-14) -1723023332*a(n-15) -3753952336*a(n-16) +1173055984*a(n-17) +3382164960*a(n-18) -244043008*a(n-19) -1495422976*a(n-20) -17107712*a(n-21) +299094528*a(n-22) +3904512*a(n-23) -19066880*a(n-24) for n>27

EXAMPLE

Some solutions for n=3

.12.10.12...12.10.12...12.14.12....0..8.10....8.14..8....0..8..0....8.14..8

.12.10..2....2.10..8....6.14..6...14..8..0....8.14..8....0..7..6....8.14..6

..2..3..2...12.10..8....6..5..6...14..8.10....8..0..1....6.14.12....6..7.15

.11..3.11....8.10..8....6..5..4...10.12.10....8..0..7....8.10.12....6..7..6

CROSSREFS

Sequence in context: A188105 A188097 A223602 * A202939 A069277 A202932

Adjacent sequences: A223692 A223693 A223694 * A223696 A223697 A223698

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 25 2013

STATUS

approved