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 A305026 #22 Jun 22 2019 09:17:08 %S A305026 39,55,354,578,1634,1644,6604,8253,9825,12573,13516,14749,15244,16684, %T A305026 18669,18672,19276,19564,21032,22225,25305,28449,29853,31688,33633, %U A305026 35793,41261,41768,41949,42813,48013,50670,54048,59750,60804,63609,63869,65265,78832 %N A305026 Numbers k such that sopfr(k) = tau(k)^2. %C A305026 For numbers k that satisfy the condition, tau(k) will always be even because tau(k) is odd only if k is a square, but if k is a square then sopfr(k) is even (because every prime appears with an even exponent) and thus it cannot be equal to tau(k)^2 which is odd as tau(k). - _Giovanni Resta_, May 24 2018 %H A305026 Amiram Eldar, <a href="/A305026/b305026.txt">Table of n, a(n) for n = 1..1000</a> %F A305026 k such that A001414(k) = A000005(k)^2. %t A305026 Rest@ Select[Range[10^5], Total[Times @@@ FactorInteger@ #] == DivisorSigma[0, #]^2 &] (* _Michael De Vlieger_, May 27 2018 *) %o A305026 (PARI) isok(n) = my(f=factor(n)); sum(k=1,#f~,f[k,1]*f[k,2]) == numdiv(n)^2; \\ _Michel Marcus_, May 24 2018 %Y A305026 Cf. A000005, A001414, A078511. %K A305026 nonn %O A305026 1,1 %A A305026 _Parker Grootenhuis_, May 23 2018