A271509 List of 5-tuples: primitive integral pentagon sides in Cairo tiling.

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

Offset: 1

Author

Kival Ngaokrajang, Apr 09 2016

Keywords

• nonn
• tabf

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.

Examples

			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,
...
		

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

Crossrefs

Cf. A103606.