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 A307507 #19 Sep 14 2022 11:59:45
%S A307507 10,14,15,21,22,26,33,34,35,38,39,46,51,55,57,58,62,65,69,74,77,82,85,
%T A307507 86,87,91,93,94,95,106,111,115,118,119,121,122,123,129,133,134,141,
%U A307507 142,143,145,146,155,158,159,161,166,177,178,183,185,187,194,201,202,203,205,206,209,213,214,215,217,218
%N A307507 Brazilian semiprimes.
%C A307507 Comparison with A001358 (semiprimes): in this sequence, there are no squared primes apart from 121 = (11111)_3, and also 6 is missing from here since it is not Brazilian.
%C A307507 Different from the squarefree semiprimes of A006881: this sequence = {A006881 \ 6} Union {121}.
%e A307507 a(20) = 74 = 2 * 37 = (22)_36 is semiprime and Brazilian.
%e A307507 25 = 5 * 5 is semiprime and no Brazilian, and 45 = (55)_8 = (33)_14 = 3^2 * 5 is Brazilian but no semiprime.
%Y A307507 Intersection of A001358 and A125134.
%Y A307507 Cf. A006881, A190300, A196104.
%K A307507 nonn,base
%O A307507 1,1
%A A307507 _Bernard Schott_, Apr 11 2019