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 A337674 #14 Oct 08 2020 03:26:47 %S A337674 1,2,4,6,8,9,12,16,18,20,24,27,30,32,36,40,42,45,48,50,54,56,60,64,70, %T A337674 72,75,80,81,84,90,96,100,105,108,112,120,126,128,132,135,140,144,150, %U A337674 160,162,168,180,189,192,196,198,200,210,216,220,224,225,240,243,250 %N A337674 Numbers k whose prime divisors are all less than or equal to the number of divisors of k. %C A337674 Density: 33 terms between 1 and 100, 17 between 201 and 300, 11 between 1001 and 1100, and 2 between 1000001 and 1000100. %e A337674 42=a(17) is a term, since 2,3 and 7 are the prime divisors of 42, which has 8 divisors. 156=2^2*3*13 is not a term, since 13 is greater than 12, the number of divisors of 156. %t A337674 Select[Range[250], FactorInteger[#][[-1, 1]] <= DivisorSigma[0, #] &] (* _Amiram Eldar_, Sep 22 2020 *) %o A337674 (PARI) isok(m) = #select(x->(x>numdiv(m)), factor(m)[,1]) == 0; \\ _Michel Marcus_, Sep 22 2020 %Y A337674 A199768 has "strictly less", while this sequence has "less than or equal to". %Y A337674 The union of A199768 and A036878. %Y A337674 A146982 does not include terms 42, 56, 132, 198, 220, 264, 308, 312, 330, ... %Y A337674 Cf. A000005. %K A337674 nonn %O A337674 1,2 %A A337674 _Richard Peterson_, Sep 15 2020