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 A071340 #11 Jul 14 2024 03:49:10 %S A071340 0,1,1,5,5,25,25,25,25,65,65,65,65,65,65,65,65,65,65,325,325,325,325, %T A071340 325,325,325,325,325,325,325,325,325,325,325,1105,1105,1105,1105,1105, %U A071340 1105,1105,1105,1105,1105,1105,1105,1105,1105,1105,1105,1105,1105,1105 %N A071340 a(n) = least positive r <= n such that the origin-centered circle of radius sqrt(r) touches A071339(n) lattice points. %H A071340 Hugo Pfoertner, <a href="https://www.randomwalk.de/sequences/a071340.gif">Illustration</a> %e A071340 a(4)=5 because the smallest circle to touch A071339(4)=8 points has radius sqrt(5). %o A071340 (FORTRAN) See A071339. %Y A071340 Cf. A071339-A071347. %K A071340 easy,nonn %O A071340 0,4 %A A071340 _Hugo Pfoertner_, May 22 2002 %E A071340 Edited by _Don Reble_, Nov 06 2005