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 A048523 #14 Nov 09 2018 21:13:12
%S A048523 13,19,37,53,71,73,97,103,127,163,181,233,271,307,383,389,431,433,499,
%T A048523 509,563,587,631,701,743,787,811,857,859,947,1009,1049,1061,1087,1153,
%U A048523 1171,1223,1283,1423,1483,1489,1553,1597,1601,1607,1733,1801,1861,1867
%N A048523 Primes for which only one iteration of 'Prime plus its digit sum equals a prime' is possible.
%C A048523 Sequence A048519 lists the primes for which at least (rather than exactly) one iteration of A062028 is "possible". See A048524 .. A048527 and A320878 .. A320880 for further subsequences, and A090009 for the list of their initial terms, starting chains of length >= 3 .. 9. - _M. F. Hasler_, Nov 09 2018
%H A048523 Harvey P. Dale, <a href="/A048523/b048523.txt">Table of n, a(n) for n = 1..1000</a>
%e A048523 prime 1999 -> 1999 + (1+9+9+9) = prime 2027 -> next iteration yields composite 2038.
%t A048523 ppd1Q[n_]:=PrimeQ[Rest[NestList[#+Total[IntegerDigits[#]]&,n,2]]] == {True,False}; Select[Prime[Range[300]],ppd1Q] (* _Harvey P. Dale_, Nov 10 2011 *)
%Y A048523 Cf. A047791, A048519.
%K A048523 nonn,base
%O A048523 1,1
%A A048523 _Patrick De Geest_, May 15 1999