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 A199981 #10 Aug 03 2014 14:01:36
%S A199981 12,21,26,34,62,112,121,126,134,143,162,216,232,261,278,279,287,297,
%T A199981 299,314,322,341,369,371,376,396,398,413,447,469,474,496,612,621,637,
%U A199981 639,649,666,693,694,713,728,729,731,736,744,763,782,792,872,893,927,936
%N A199981 Composite numbers whose multiplicative digital root is 2.
%C A199981 Complement of A199980 with respect to A034049.
%e A199981 Number 278 is in sequence because 2*7*8=112, 1*1*2 =2.
%t A199981 t = {}; n = 0; While[Length[t] < 100, n = n + 1; If[! PrimeQ[n], s = n; While[s >= 10, s = Times @@ IntegerDigits[s]]; If[s == 2, AppendTo[t, n]]]]; t (* _T. D. Noe_, Nov 16 2011 *)
%Y A199981 Cf. A199980 (primes whose multiplicative digital root is 2).
%Y A199981 Cf. A034049 (numbers whose multiplicative digital root is 2).
%K A199981 nonn,base
%O A199981 1,1
%A A199981 _Jaroslav Krizek_, Nov 13 2011