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 A158281 #5 Feb 01 2015 00:16:02
%S A158281 2,3,5,7,13,29,31,41,47,53,61,79,83,97,101,113,131,139,151,157,193,
%T A158281 199,211,223,227,241,263,269,311,313,331,337,353,359,373,379,397,401,
%U A158281 409,421,443,463,487,557,571,593,599,601,607,643,661,683,733,739,751,773
%N A158281 Prime numbers p such that prime = abs(smallest digit of p - sum of all the other digits of p).
%H A158281 Harvey P. Dale, <a href="/A158281/b158281.txt">Table of n, a(n) for n = 1..1000</a>
%e A158281 13(2=abs(1-3)), 29(7=abs(2-9)), 31(2=3-1)
%t A158281 sdsodQ[n_]:=Module[{sidn=Sort[IntegerDigits[n]]},PrimeQ[Abs[sidn[[1]]-Total[Rest[sidn]]]]]; Select[Prime[Range[150]],sdsodQ] (* _Harvey P. Dale_, Feb 01 2015 *)
%Y A158281 Cf. A000040, A156979.
%K A158281 nonn,base
%O A158281 1,1
%A A158281 _Juri-Stepan Gerasimov_, Mar 15 2009, May 25 2009
%E A158281 Single-digit primes added, duplicates of 421 and 443 removed - _R. J. Mathar_, May 19 2010