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 A152985 #9 Jan 28 2014 16:53:57 %S A152985 0,1,2,11,4,47,6,57,36,109,10,245,12,195,170,247,16,509,18,547,292, %T A152985 439,22,1055,152,597,358,969,28,1895,30,1013,632,985,534,2431,36,1215, %U A152985 850,2317,40,3397,42,2173,1712,1747,46,4313,396,2953,1382,2955,52,4715,1090,4083 %N A152985 Sum of proper divisors minus the number of proper divisors of the square A000290(n). %H A152985 B. D. Swan, <a href="/A152985/b152985.txt">Table of n, a(n) for n=1,...,50000</a> %F A152985 a(n) = A001065(A000290(n)) - A032741(A000290(n)) = A152770(A000290(n)). %o A152985 (PARI) a(n) = sigma(n^2) - n^2 - (numdiv(n^2) - 1); \\ _Michel Marcus_, Jan 28 2014 %Y A152985 Cf. A000005, A000203, A000290, A001065, A032741, A152770. %K A152985 nonn,look %O A152985 1,3 %A A152985 _Omar E. Pol_, Dec 21 2008