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 A374484 #26 Sep 19 2024 08:22:41
%S A374484 1,2,3,4,6,7,9,12,13,17,19,22,27,28,34,37,41,48,49,56,62,65,74,77,84,
%T A374484 93,95,106,111,118,130,131,143,152,157,171,175,186,199,202,218,225,
%U A374484 235,252,253,271,281,290,309,312,329,344,350,371,378,393,413,416,439
%N A374484 Index of A006899(n) in A003586.
%C A374484 Index of powers of 2 and 3 in 3-smooth numbers.
%H A374484 Amiram Eldar, <a href="/A374484/b374484.txt">Table of n, a(n) for n = 1..10000</a>
%F A374484 A003586(a(n)) = A006899(n).
%F A374484 a(n) ~ c * n^2, where c = log(2)*log(3)/(2*(log(2) + log(3))^2) = 0.118598856384648... - _Vaclav Kotesovec_ and _Amiram Eldar_, Sep 19 2024
%e A374484 A006899(10) = 64 which is the 17th term of A003586, therefore a(10) = 17.
%t A374484 seq[lim_] := Position[Times @@ IntegerExponent[#, {2, 3}] & /@ Sort[Flatten[ Table[2^i*3^j, {i, 0, Log2[lim]}, {j, 0, Log[3, lim/2^i]}] ]], 0] // Flatten; seq[10^11] (* _Amiram Eldar_, Sep 18 2024 *)
%o A374484 (Python)
%o A374484 from sympy import integer_log
%o A374484 def A374484(n): return sum(((1<<k)//3**i).bit_length() for i in range(integer_log(1<<k,3)[0]+1)) if integer_log(m:=3**(n-1),6)[0]<(k:=integer_log(3*m,6)[0]) else sum((3**i).bit_length() for i in range(integer_log(1<<n,6)[0]+1))
%Y A374484 Cf. A003586, A006899.
%Y A374484 Disjoint union of A022330 and A022331.
%K A374484 nonn,easy
%O A374484 1,2
%A A374484 _Chai Wah Wu_, Sep 16 2024