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 A226480 #5 Jun 09 2013 11:32:10 %S A226480 22446139,26116291,28097023,30236557,31090489,31124341,49941589, %T A226480 61137673,62224039,66960589,71334867,71585139,82266591,83045869, %U A226480 92346023,92837591,105183961,114762567,123563821,130399138,131494219,134156197,134867722,135095767,136026037 %N A226480 Squarefree numbers n such that (sopf(n)*d(n))^2 = sigma(n) where sopf(n) = sum of prime factors of n and d(n) = number of divisors of n. %C A226480 Suggested by _N. J. A. Sloane_. %H A226480 Donovan Johnson, <a href="/A226480/b226480.txt">Table of n, a(n) for n = 1..500</a> %e A226480 n = 22446139 = 31*67*101*107. sopf(n) = 31+67+101+107 = 306. d(n) = 16. (sopf(n)*d(n))^2 = (306*16)^2 = 23970816 = sigma(n). %Y A226480 Cf. A000005, A000203, A006532, A008472, A126028, A226479. %K A226480 nonn %O A226480 1,1 %A A226480 _Donovan Johnson_, Jun 09 2013