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 A271509 List of 5-tuples: primitive integral pentagon sides in Cairo tiling. 1
 5, 5, 5, 5, 2, 13, 13, 13, 13, 14, 17, 17, 17, 17, 14, 25, 25, 25, 25, 34, 29, 29, 29, 29, 2, 37, 37, 37, 37, 46, 41, 41, 41, 41, 62, 53, 53, 53, 53, 34, 61, 61, 61, 61, 98, 65, 65, 65, 65, 94, 65, 65, 65, 65, 46, 73, 73, 73, 73, 14 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Refer to Cairo tiling by Stick Cross Method (see details in the links). Each pentagon has four sides of equal length and one side which is either shorter or longer. All sides can be taken to have integral lengths related to primitive Pythagorean triples A103606. If Pythagorean triple = (a, b, c), the 5-tuple is (s1, s2, s3, s4, s5) with s1 = s2 = s3 = s4 = c and s5 = 2*(b-a). See illustration in the links. LINKS David Bailey's World of Escher-like Tessellations, Stick Cross Method Kival Ngaokrajang, Illustration of initial terms, Excel calculation sheet Wikipedia, Cairo pentagonal tiling EXAMPLE List begins: 5, 5, 5, 5, 2, 13, 13, 13, 13, 14, 17, 17, 17, 17, 14, 25, 25, 25, 25, 34, 29, 29, 29, 29, 2, ... CROSSREFS Cf. A103606. Sequence in context: A083945 A125563 A093704 * A269626 A269268 A112110 Adjacent sequences:  A271506 A271507 A271508 * A271510 A271511 A271512 KEYWORD nonn,tabf AUTHOR Kival Ngaokrajang, Apr 09 2016 STATUS approved

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Last modified October 21 22:22 EDT 2018. Contains 316430 sequences. (Running on oeis4.)