A087456 Palindromic hypotenuses in primitive Pythagorean triples.

5, 101, 181, 313, 353, 373, 505, 545, 565, 757, 797, 929, 949, 10001, 10201, 10301, 10501, 10601, 12421, 12721, 12821, 14341, 14741, 16061, 16361, 16561, 16661, 16861, 18181, 18281, 18481, 18581, 31013, 31313, 31513, 31613, 31813, 33133

Offset: 1

Author

Lekraj Beedassy, Oct 23 2003

Keywords

• nonn
• base

Comments

For prime terms in this sequence, see A081220. - Lekraj Beedassy, Jun 30 2008

Crossrefs

Cf. A020882.

Programs

Mathematica

Take[Select[Sqrt[#[[1]]^2+#[[2]]^2]&/@(Union[Sort/@({Times@@#,(Last[#]^2- First[#]^2)/2}&/@(Select[Subsets[Range[1,311,2],{2}],GCD@@#== 1&]))]), PalindromeQ]//Union,50] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 06 2018 *)

Extensions

More terms from Ray Chandler, Oct 25 2003