A120681 Sum of legs of primitive Pythagorean triangles sorted first on hypotenuse, then long leg.

7, 17, 23, 31, 41, 47, 49, 73, 71, 89, 79, 103, 113, 97, 119, 137, 119, 151, 127, 161, 193, 167, 161, 191, 217, 239, 217, 199, 257, 233, 263, 223, 289, 271, 311, 241, 281, 313, 329, 287, 343, 287, 329, 367, 391, 401, 353, 431, 409, 337, 383, 457, 359, 463, 479

Offset

1,1

Comments

The prime numbers congruent to +1 or -1 modulo 8 of this sequence appear exactly once. For a proof see the W. Lang link under A001132. - Wolfdieter Lang, Feb 17 2015

Links

Ray Chandler, Table of n, a(n) for n = 1..10000

Formula

a(n) = A046087(n) + A046086(n).

Mathematica

A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import["https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {_, _}][[All, 2]]];
A046086 = A@046086;
A046087 = A@046087;
a[n_] := A046087[[n]] + A046086[[n]];
a /@ Range[10000] (* Jean-François Alcover, Mar 07 2020 *)

Crossrefs

Cf. A120682, A058529, A118905, A198390, A001132, A046086, A046087.

Sequence in context: A198441 A058529 A253408 * A270951 A001132 A308816

Adjacent sequences: A120678 A120679 A120680 * A120682 A120683 A120684

Keyword

nonn

Author

Lekraj Beedassy, Jun 24 2006

Extensions

Edited and corrected by Ray Chandler, Apr 10 2010

Status

approved