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.

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A316842 Three-column table read by rows giving primitive integer sides of proper triangles (i,j,k) with i >= j >= k >= 1, j+k > i, gcd(i,j,k) = 1.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 3, 2, 2, 3, 3, 1, 3, 3, 2, 4, 3, 2, 4, 3, 3, 4, 4, 1, 4, 4, 3, 5, 3, 3, 5, 4, 2, 5, 4, 3, 5, 4, 4, 5, 5, 1, 5, 5, 2, 5, 5, 3, 5, 5, 4, 6, 4, 3, 6, 5, 2, 6, 5, 3, 6, 5, 4, 6, 5, 5, 6, 6, 1, 6, 6, 5, 7, 4, 4, 7, 5, 3, 7, 5, 4, 7, 5, 5, 7, 6, 2, 7, 6, 3, 7, 6, 4, 7, 6, 5, 7, 6, 6, 7, 7, 1, 7, 7, 2, 7, 7, 3, 7, 7, 4, 7, 7, 5, 7, 7, 6, 8, 5, 4
Offset: 1

Views

Author

N. J. A. Sloane, Jul 23 2018, following a suggestion from Donald S. McDonald

Keywords

Examples

			Table begins:
[1,1,1],
[2,2,1],
[3,2,2],
[3,3,1],
[3,3,2],
[4,3,2],
[4,3,3],
[4,4,1],
[4,4,3],
[5,3,3],
[5,4,2],
...
		

Crossrefs

There are A123323(k) rows that begin with k.
The three columns are A316846, A316847, A316848.
A316850 is a compressed version.
See A316841 for all triples (including imprimitive triples).
See A316852 and A317181 & A317183 for perimeter and area.
Other related sequences: A051493, A070080, A070081, A070082, A070110.

A317183 Numbers k such that k = 16*area(T)^2 for a primitive integer triangle, T.

Original entry on oeis.org

3, 15, 35, 63, 99, 128, 135, 143, 195, 231, 255, 275, 320, 323, 351, 384, 399, 455, 483, 495, 575, 576, 663, 675, 735, 768, 783, 819, 855, 896, 899, 935, 975, 1023, 1071, 1155, 1235, 1280, 1295, 1311, 1344, 1443, 1463, 1536, 1539, 1575, 1599, 1683, 1728, 1763
Offset: 1

Views

Author

N. J. A. Sloane, Jul 25 2018

Keywords

Comments

A316842 lists the primitive integer triangles.

Crossrefs

Cf. A316842.
Sorted and uniqued values of A317181.
Subsequence of A317182.

Extensions

Terms a(13) and beyond from Lars Blomberg, Jul 27 2018
Name edited by Peter Munn, Jul 30 2025
Showing 1-2 of 2 results.