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 A135773 #11 Nov 09 2016 02:34:17
%S A135773 1,3,5,7,9,25,27,33,34,35,38,39,46,51,55,57,58,62,65,69,74,77,81,243,
%T A135773 244,245,261,268,275,279,284,292,316,325,332,333,338,356,363,369,387,
%U A135773 388,404,412,423,425,428,436,452,475,477,507,508,524,531,539,548,549
%N A135773 Numbers having number of divisors equal to number of digits in base 3.
%C A135773 Since 3 is a prime, any power 3^k has k+1 divisors { 3^i ; i=0..k } and the same number of digits in base 3; thus the sequence A000244(k) = 3^k is a subsequence of this one. Note that no number in between 3^4 and 3^5, neither in between 3^6 and 3^7, is in this sequence.
%H A135773 G. C. Greubel, <a href="/A135773/b135773.txt">Table of n, a(n) for n = 1..1250</a>
%e A135773 a(1) = 1 since 1 has 1 divisor and 1 digit (in base 3).
%e A135773 2 has 2 divisors but only 1 digit in base 3, so it is not member of the sequence.
%e A135773 a(2)..a(4) = 3, 5, 7 all have 2 divisors and 2 digits in base 3.
%e A135773 81 = 3^4 = 10000_3 is the only number with 5 divisors and 5 digits in base 3, so it is followed by 243 = 3^5 = 100000_3.
%t A135773 Select[Range[500], DivisorSigma[0, #] == IntegerLength[#, 3] &] (* _G. C. Greubel_, Nov 08 2016 *)
%o A135773 (PARI) for(d=1,6,for(n=3^(d-1),3^d-1,d==numdiv(n)&print1(n", ")))
%Y A135773 Cf. A135772 - A135779, A095862.
%K A135773 base,nonn
%O A135773 1,2
%A A135773 _M. F. Hasler_, Nov 28 2007