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 A071347 #5 Oct 19 2017 03:14:02 %S A071347 1,3,9,15,18,30,42,54,78,90,114,126,150,186,210,210,270,270,330,390, %T A071347 390,450,510,570,594,630,630,750,810,882,930,990,1050,1050,1170,1170, %U A071347 1350,1386,1470,1530,1650,1710,1710,1890,1890,1890,1890,2250,2310 %N A071347 a(n) = greatest positive r <= n, such that the origin-centered 4d-sphere of radius sqrt(r) touches A071345(n) lattice points. %e A071347 a(4)=15 because the largest 4d-sphere with radius <= 4 to touch A071345(4)=192 points has radius sqrt(15). %o A071347 (FORTRAN) See A071339. %Y A071347 Cf. A071339-A071346. %K A071347 easy,nonn %O A071347 1,2 %A A071347 _Hugo Pfoertner_, May 22 2002 %E A071347 Edited by _Don Reble_, Nov 06 2005