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 A093618 #21 Apr 15 2024 03:36:22
%S A093618 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,19,20,21,22,23,24,25,26,27,
%T A093618 28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,51,
%U A093618 52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74
%N A093618 Numbers m such that for all k less than m the number of divisors of k*m and m^2 are different.
%H A093618 Amiram Eldar, <a href="/A093618/b093618.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1800 from Vincenzo Librandi)
%F A093618 A093616(a(n)) = n.
%t A093618 A093616[n_] := For[k = 1, True, k++, If[DivisorSigma[0, k*n] == DivisorSigma[0, n^2], Return[k]]]; Select[Range[100], A093616[#] == # &] (* _Jean-François Alcover_, Aug 14 2014 *)
%o A093618 (PARI) is(n) = {my(k = 1, d = numdiv(n^2)); while(k < n && numdiv(k*n) != d, k++); k == n;} \\ _Amiram Eldar_, Apr 15 2024
%Y A093618 Complement of A093617.
%Y A093618 Cf. A000005, A000290, A048691, A093616.
%K A093618 nonn
%O A093618 1,2
%A A093618 _Reinhard Zumkeller_, Apr 06 2004
%E A093618 Corrected by _Franklin T. Adams-Watters_, Dec 19 2006