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 A071341 #6 Oct 19 2017 03:14:02 %S A071341 0,1,4,5,13,25,25,25,50,65,85,85,130,145,185,221,250,265,305,325,325, %T A071341 425,425,425,425,425,650,725,725,725,850,925,925,1025,1105,1105,1105, %U A071341 1105,1105,1105,1105,1625,1625,1625,1885,1885,1885,2125,2210 %N A071341 a(n) = greatest positive r <= n, such that the origin-centered circle of radius sqrt(r) touches A071339(n) lattice points. %e A071341 a(4)=13 because the largest circle with radius <= 4 to touch A071339(4)=8 points has radius sqrt(13). %o A071341 (FORTRAN) See A071339. %Y A071341 Cf. A071339-A071347. %K A071341 easy,nonn %O A071341 0,3 %A A071341 _Hugo Pfoertner_, May 22 2002 %E A071341 Edited by _Don Reble_, Nov 06 2005