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 A061289 Consider a network of triangles consisting of an equilateral triangle divided into n^2 equilateral triangles plus a circle connecting the vertices of the main triangle. Sequence gives minimal number of corner turns required to trace the network in one continuous line. 0
 3, 7, 13, 17, 20, 23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES Mohammad K. Azarian, A Trigonometric Characterization of  Equilateral Triangle, Problem 336, Mathematics and Computer Education, Vol. 31, No. 1, Winter 1997, p. 96.  Solution published in Vol. 32, No. 1, Winter 1998, pp. 84-85. Mohammad K. Azarian, Equating Distances and Altitude in an Equilateral Triangle, Problem 316, Mathematics and Computer Education, Vol. 28, No. 3, Fall 1994, p. 337.  Solution published in Vol. 29, No. 3, Fall 1995, pp. 324-325. Martin Gardner, More Mathematical Puzzles and Diversions, page 63, "a network tracing puzzle". LINKS EXAMPLE a(1)=3 since you have to make two turns to trace the triangle and one to cover the circular part of the network. CROSSREFS Sequence in context: A124273 A038923 A310254 * A310255 A285669 A063239 Adjacent sequences:  A061286 A061287 A061288 * A061290 A061291 A061292 KEYWORD hard,nonn AUTHOR Brian Wallace (wallacebrianedward(AT)yahoo.co.uk), May 22 2001 STATUS approved

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Last modified April 10 22:05 EDT 2021. Contains 342856 sequences. (Running on oeis4.)