A297878 1/4 of the even edges of primitive Pythagorean triangles with legs (b=A081872, c=A081859), ordered by semiperimeters.
1, 3, 2, 6, 5, 3, 10, 7, 15, 4, 14, 12, 21, 9, 20, 5, 18, 28, 15, 11, 36, 6, 22, 35, 33, 45, 13, 30, 44, 7, 26, 42, 55, 21, 39, 15, 35, 8, 52, 66, 30, 65, 24, 63, 17, 78, 40, 9, 60, 77, 34, 56, 91, 51, 19, 72, 45, 10, 68, 88, 105, 38, 63, 85, 30, 104, 57, 21, 102, 120, 11, 76, 99, 42, 119, 70, 33, 95
Offset: 1
Keywords
Examples
From _Michel Marcus_, Mar 07 2018: (Start) The first 10 terms of A081859 are 3, 5, 8, 7, 20, 12, 9, 28, 11, 16; The first 10 terms of A081872 are 4, 12, 15, 24, 21, 35, 40, 45, 60, 63; So the first 10 even legs are 4, 12, 8, 24, 20, 12, 40, 28, 60, 16; So the first 10 terms are 1, 3, 2, 6, 5, 3, 10, 7, 15, 4. (End)
Links
- Wikipedia, Pythagorean triple.
- Lindsey Witcosky, Perimeters of primitive Pythagorean triangles.
- Index entries related to Pythagorean Triples.
Crossrefs
Programs
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Mathematica
(* lists a0* have to be prepared before *) opPT = {a020882, a046087, a046086, a020882 + a046087 + a046086} topPT = Transpose[opPT]; stopPT = SortBy[topPT, {#[[4]]} &]; tstopPT = Transpose[stopPT]; nopPT = tstopPT; Do[ If[OddQ[tstopPT[[2]][[k]]], nopPT[[2]][[k]] = tstopPT[[2]][[k]]; nopPT[[3]][[k]] = tstopPT[[3]][[k]], nopPT[[2]][[k]] = tstopPT[[3]][[k]]; nopPT[[3]][[k]] = tstopPT[[2]][[k]]], {k, 1, 10000}]; nopPT[[3]]/4
Comments