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 A178849 #4 Mar 31 2012 14:41:48
%S A178849 2,9,14,343,44,28561,135,110,6436343,1225,464,228,4750104241,3087,
%T A178849 1376,696,2488651484819,15376,1452,4288,1218,456533,1968,
%U A178849 3936588805702081,89888,2646,12928,2070,810448,5152,8594754748609397887,440896,7938
%N A178849 n-th integer having n-th prime-containing prime signature.
%C A178849 This sequence forms the diagonal of the table (A095904) containing all of the integers >= 2, ordered by prime signature.
%C A178849 The first row of the table is A025487 (starting with n=2),
%C A178849 The first column of the table is the primes (A000040).
%C A178849 The description for this sequence specifies "prime-containing" to exclude the prime signature for 1, which is also excluded from A095904.
%e A178849 The 5th prime-containing prime signature (i.e. excluding the prime signature for 1) is {1,2}.
%e A178849 The 5th integer to have that prime signature is 44 (see A054753 for a list).
%e A178849 Therefore a(5) is 44.
%Y A178849 Cf. A025487, A000040, A095904.
%K A178849 nonn
%O A178849 1,1
%A A178849 _Will Nicholes_, Jun 17 2010
%E A178849 Extended by _Ray Chandler_, Aug 01 2010