RMM Number3 March 2015 Hi
Edition Associa¸c˜ao Ludus, Museu Nacional de Hist´oria Natural e da Ciˆencia, Rua da Escola Polit´ecnica 56 1250-102 Lisboa, Portugal email: rmm@ludus-opuscula.org URL: http://rmm.ludus-opuscula.org Managing Editor Carlos Pereira dos Santos, cmfsantos@fc.ul.pt Center for Linear Structures and Combinatorics, University of Lisbon Editorial Board Aviezri S. Fraenkel, Aviezri.Fraenkel@weizmann.ac.il, Weizmann Institute Carlos Pereira dos Santos Colin Wright, juggler@solipsys.co.uk, Liverpool Mathematical Society David Singmaster, zingmast@gmail.com, London South Bank University David Wolfe, davidgameswolfe@gmail.com, Gustavus Adolphus College Edward Pegg, ed@mathpuzzle.com, Wolfram Research Jo˜ao Pedro Neto, jpn@di.fc.ul.pt, University of Lisbon Jorge Nuno Silva, jnsilva@cal.berkeley.edu, University of Lisbon Keith Devlin, kdevlin@stanford.edu, Stanford University Richard Nowakowski, rjn@mathstat.dal.ca, Dalhousie University Robin Wilson, r.j.wilson@open.ac.uk, Open University Thane Plambeck, tplambeck@gmail.com, Counterwave, inc Informations The Recreational Mathematics Magazine is electronic and semiannual. The issues are published in the exact moments of the equinox. The magazine has the following sections (not mandatory in all issues): Articles Games and Puzzles Problems MathMagic Mathematics and Arts Math and Fun with Algorithms Reviews News ISSN 2182-1976 Contents Page Math and Fun with Algorithms: Xiang-Sheng Wang Calculating the day of the week: null-days algorithm . 5 Games and Puzzles: David Singmaster Some early topological puzzles – Part 1 ............ 9 Mathematics and Arts: Pedro Freitas Almada Negreiros and the regular nonagon .......... 39 Mathematics and Arts: Ricardo Cunha Teixeira Patterns, mathematics and culture: The search for symme- try in Azorean sidewalks and traditional crafts ......
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