A097102 - OEIS

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A097102

Numbers n that are the hypotenuse of exactly 13 distinct integer-sided right triangles, i.e., n^2 can be written as a sum of two squares in 13 ways.

1105, 1885, 2210, 2405, 2465, 2665, 3145, 3315, 3445, 3485, 3770, 3965, 4420, 4505, 4745, 4810, 4930, 5185, 5330, 5365, 5655, 5785, 5945, 6205, 6290, 6305, 6409, 6565, 6630, 6890, 6970, 7085, 7215, 7345, 7395, 7540, 7565, 7585, 7685, 7735, 7930, 7995

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

If m is a term, then 2*m and p*m are terms where p is any prime of the form 4k+3. - Ray Chandler, Dec 30 2019

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

MATHEMATICA

r[a_]:={b, c}/.{ToRules[Reduce[0<b<c&&a^2 == b^2 + c^2, {b, c}, Integers]]}; Select[Range[5000], Length[r[#]] == 13 &] (* Vincenzo Librandi, Mar 01 2016 *)

CROSSREFS

Cf. A004144 (0), A084645 (1), A084646 (2), A084647 (3), A084648 (4), A084649 (5), A097219 (6), A097101 (7), A290499 (8), A290500 (9), A097225 (10), A290501 (11), A097226 (12), A290502 (14), A290503 (15), A097238 (16), A097239 (17), A290504 (18), A290505 (19), A097103 (22), A097244 (31), A097245 (37), A097282 (40), A097626 (67).

Sequence in context: A025287 A025305 A052155 * A281877 A159781 A264498

Adjacent sequences: A097099 A097100 A097101 * A097103 A097104 A097105

KEYWORD

nonn

AUTHOR

James R. Buddenhagen, Sep 15 2004

EXTENSIONS

More terms from Ray Chandler, Sep 16 2004

Definition corrected by Zak Seidov, Feb 26 2008

STATUS

approved