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.
%I A096891 #21 Apr 06 2017 21:27:30
%S A096891 5,13,25,41,61,85,17,145,181,29,265,313,365,421,481,65,37,685,89,841,
%T A096891 925,53,1105,1201,149,1405,73,185,1741,1861,65,97,2245,269,2521,2665,
%U A096891 317,85,3121,3281,3445,157,425,3961,109,485,193,4705,101,5101,5305,137
%N A096891 Least hypotenuse of primitive Pythagorean triangles with odd leg 2n+1.
%C A096891 Ordered terms are A020882. - _Paul Curtz_, Sep 08 2008
%C A096891 Least value of x^2 + y^2 with gcd(x,y) = 1 such that y^2 - x^2 = 2n+1. - _Thomas Ordowski_, Apr 02 2017
%t A096891 f[n_] := Block[{k = 2}, While[c = Sqrt[(2n + 1)^2 + k^2]; ! IntegerQ@ c || GCD[2n + 1, c, k] > 1, k += 2]; c]; Array[f, 52] (* _Robert G. Wilson v_, Mar 18 2014 *)
%Y A096891 Cf. A020882, A088557, A088558, A096891, A096892, A096893, A096894, A096895, A096896, A096897, A096898, A096899, A096900.
%K A096891 nonn
%O A096891 1,1
%A A096891 _Ray Chandler_, Jul 14 2004