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 A256154 #20 Apr 14 2015 16:45:55
%S A256154 3,5,7,33,311,57,37,313,53,511,319,59,73,355,711,79,331,519,97,3311,
%T A256154 3337,567,337,3113,353,571,3717,359,373,3555,1329,379,3131,579,397,
%U A256154 3719,1341,5107,3179,7711,779,3537,557,1343,3191,5523,577,3193,593,5717,3199,599,733,3577,1167,739,3251,5151
%N A256154 Concatenation of odd prime factors of m such that the decimal digits of m only have odd prime factors.
%C A256154 Numbers in the sequence m cannot have even digits and 1: {3, 5, 7, 9, 33, 35, 37, 39, 53, ..., 99, 333, 335, ...}.
%C A256154 Subset of A256935.
%e A256154 a(5) = 33 because m(5) = 9, whose odd prime factors are 3 * 3, thus 33 is the concatenation of the factors.
%t A256154 f[n_] := Block[{of = Select[Table[#1, {#2}] & @@@ FactorInteger@ n // Flatten, PrimeQ@ # && # > 2 &]}, IntegerDigits@ of // Flatten // FromDigits]; f /@ Select[Range@ 755, Plus @@ Pick[DigitCount@#, {1, 1, 0, 1, 0, 1, 0, 1, 0, 1}, 1] == 0 &] (* _Michael De Vlieger_, Apr 14 2015 *)
%Y A256154 Cf. A119603, A256935.
%K A256154 nonn,base
%O A256154 1,1
%A A256154 _Giovanni Teofilatto_, Apr 14 2015