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 A087596 #8 Dec 05 2013 19:56:32
%S A087596 97,997,9967,99989,999907,9999907,99999989,999999607,9999999967,
%T A087596 99999999947,999999999989,9999999999701,99999999999923,
%U A087596 999999999999989,9999999999999887,99999999999999997,999999999999999989
%N A087596 Largest n-digit member of A087593. Define dd(k) = the number formed by concatenating the absolute difference of successive digits of k. Sequence contains largest n-digit prime p such that dd(p) is also prime.
%C A087596 Conjecture: Sequence is infinite.
%e A087596 a(5) = 99989 and dd(99989) = 0011 = 11 is a prime.
%t A087596 npr[n_]:=Module[{pr=NextPrime[10^n,-1]},While[!PrimeQ[FromDigits[Abs[ Differences[ IntegerDigits[pr]]]]],pr=NextPrime[pr,-1]];pr]; Array[ npr,20,2] (* _Harvey P. Dale_, Mar 06 2012 *)
%Y A087596 Cf. A087593, A087594, A087595.
%K A087596 base,nonn
%O A087596 2,1
%A A087596 _Amarnath Murthy_, Sep 18 2003
%E A087596 More terms from _David Wasserman_, Jun 15 2005