cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A099831 Perimeters of Pythagorean triangles that can be constructed in exactly 2 different ways.

Original entry on oeis.org

60, 84, 90, 132, 144, 210, 264, 270, 288, 300, 312, 330, 390, 408, 432, 440, 450, 456, 462, 468, 510, 520, 546, 552, 570, 576, 588, 612, 616, 680, 684, 690, 700, 728, 760, 770, 800, 810, 816, 828, 870, 910, 912, 918, 920, 952, 1044, 1064, 1100, 1104, 1116
Offset: 1

Views

Author

Hugo Pfoertner, Oct 27 2004

Keywords

Examples

			a(1)=60 = 10+24+26 = 15+20+25; a(2)=84 = 12+35+37 = 21+28+35.

Links

Crossrefs

Cf. A098714, A099382, A099383, A156687.

A099832 Perimeters of Pythagorean triangles that can be constructed in exactly 3 different ways.

Original entry on oeis.org

120, 168, 180, 252, 280, 336, 396, 528, 540, 560, 600, 624, 792, 864, 880, 936, 1040, 1050, 1056, 1120, 1176, 1224, 1232, 1248, 1350, 1368, 1380, 1404, 1456, 1620, 1632, 1650, 1656, 1710, 1728, 1740, 1760, 1764, 1824, 1836, 1860, 1960, 2002, 2052, 2080
Offset: 1

Views

Author

Hugo Pfoertner, Oct 27 2004

Keywords

Examples

			a(1)=120 = 20+48+52 = 24+45+51 = 30+40+50; a(2)=168 = 21+72+75 = 24+70+74 = 42+56+70.

Links

Crossrefs

Cf. A098714, A099381, A099383, A156687.

Programs

  • Mathematica
    SetSystemOptions["ReduceOptions" -> {"DiscreteSolutionBound" -> 2500}]; AllPerimeterTriples[n_Integer] /; n > 0 := Module[{result = Reduce[ Reduce[{x^2 + y^2 == z^2, z > y > x > 0, Element[{x, y, z}, Integers], x + y + z == n}, {x, y, z}]]}, If[result === False, {}, Sort[{x, y, z} /. {ToRules[result]}]]]; Select[ Range[ 2500], Length[ AllPerimeterTriples[#]] == 3 &] (* Robert G. Wilson v, Oct 17 2012 *)

A099833 Perimeters of Pythagorean triangles that can be constructed in exactly 4 different ways.

Original entry on oeis.org

240, 360, 480, 504, 630, 672, 756, 780, 900, 960, 990, 1020, 1092, 1140, 1170, 1188, 1344, 1386, 1400, 1428, 1530, 1540, 1596, 1638, 1820, 1920, 1932, 1950, 2070, 2112, 2240, 2244, 2268, 2376, 2380, 2448, 2496, 2508, 2610, 2652, 2660, 2688, 2736, 2800
Offset: 1

Views

Author

Hugo Pfoertner, Oct 27 2004

Keywords

Examples

			a(1)=240 = 15+112+113 = 40+96+104 = 48+90+102 = 60+80+100; a(2)=360 = 36+160+164 = 60+144+156 = 72+135+153 = 90+120+150.

Links

Crossrefs

Cf. A098714, A099381, A099382, A156687.
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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