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 A336068 #10 Jul 14 2020 03:38:53 %S A336068 3,6,12,15,18,21,24,27,30,33,36,39,42,48,51,54,57,60,66,69,72,75,78, %T A336068 84,87,90,93,96,102,105,108,111,114,120,123,126,129,132,135,138,141, %U A336068 144,147,150,156,159,165,168,174,177,180,183,186,189,192,195,198,201,204 %N A336068 Numbers k such that the exponent of the highest power of 3 dividing k (A007949) is a divisor of k. %C A336068 All the terms are divisible by 3 by definition. %C A336068 Šalát (1994) proved that the asymptotic density of this sequence is 0.287106... (A336069). %H A336068 Amiram Eldar, <a href="/A336068/b336068.txt">Table of n, a(n) for n = 1..10000</a> %H A336068 Tibor Šalát, <a href="https://dml.cz/handle/10338.dmlcz/129777">On the function a_p, p^a_p(n) || n (n > 1)</a>, Mathematica Slovaca, Vol. 44, No. 2 (1994), pp. 143-151. %e A336068 3 is a term since A007949(3) = 1 is a divisor of 3. %t A336068 Select[Range[200], Mod[#, 3] == 0 && Divisible[#, IntegerExponent[#, 3]] &] %o A336068 (PARI) isok(m) = if (!(m%3), (m % valuation(m,3)) == 0); \\ _Michel Marcus_, Jul 08 2020 %Y A336068 A055777 is a subsequence. %Y A336068 Cf. A007949, A336069. %Y A336068 Similar sequences: A033950, A005349, A006446, A074946, A075592, A007694, A112249, A336066. %K A336068 nonn %O A336068 1,1 %A A336068 _Amiram Eldar_, Jul 07 2020