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 A100752 #50 Oct 23 2024 11:46:05
%S A100752 1,7,20,40,67,101,142,190,244,306,376,452,534,624,720,824,935,1052,
%T A100752 1178,1309,1447,1593,1745,1905,2071,2244,2424,2611,2806,3006,3214,
%U A100752 3429,3652,3881,4117,4360,4610,4866,5131,5401,5679,5964,6255,6553,6859,7172,7491
%N A100752 a(n) is the number of positive integers <= 10^n that are divisible by no prime exceeding 3.
%C A100752 A good approximation seems to be ceiling(log(10^n)*log(6*10^n)/(log(3)*log(4))). - _Horst H. Manninger_, Oct 29 2022
%H A100752 David A. Corneth, <a href="/A100752/b100752.txt">Table of n, a(n) for n = 0..1999</a>
%F A100752 a(n) = A071521(10^n). - _Chai Wah Wu_, Oct 23 2024
%e A100752 a(1) = 7 as there are 7 3-smooth numbers less than 10^1 = 10; they are 1, 2, 3, 4, 6, 8, 9. - _David A. Corneth_, Nov 14 2019
%t A100752 f[n_] := Sum[ Floor@ Log[2, n/3^i] + 1, {i, 0, Log[3, n]}]; Table[ f[10^n], {n, 0, 46}] (* _Robert G. Wilson v_, Nov 07 2012 *)
%o A100752 (Python)
%o A100752 from sympy import integer_log
%o A100752 def A100752(n): return sum((10**n//3**i).bit_length() for i in range(integer_log(10**n,3)[0]+1)) # _Chai Wah Wu_, Oct 23 2024
%Y A100752 Cf. A003586, A011557, A071521.
%Y A100752 Cf. A066343, A106598, A106600, A107352, A106629.
%Y A100752 Row 2 of A253635.
%K A100752 nonn
%O A100752 0,2
%A A100752 _Robert G. Wilson v_, May 27 2005