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 A210994 #8 Jan 07 2013 18:26:19 %S A210994 1,2,3,4,5,7,9,11,12,13,16,17,18,19,20,23,24,25,28,29,30,31,32,36,37, %T A210994 40,41,42,43,44,45,47,48,49,50,52,53,54,56,59,60,61,63,64,66,67,68,70, %U A210994 71,72,73,75,76,78,79,80,81,83,84,88,89,90,92,96 %N A210994 Numbers n such that A000005(n) <> 4. %e A210994 6 is not in the sequence because 6 has four divisors: 1, 2, 3, 6. %t A210994 Select[Range[100],DivisorSigma[0,#]!=4&] (* _Harvey P. Dale_, Jan 07 2013 *) %Y A210994 Complement of A030513. Column 4 of A210976. %Y A210994 Cf. A018252, A213367. %K A210994 nonn %O A210994 1,2 %A A210994 _Omar E. Pol_, Aug 11 2012