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 A172508 #12 Jan 22 2019 02:48:48 %S A172508 2,3,5,7,13,29,31,41,47,53,61,79,83,97,163,257,461,479,503,613,631, %T A172508 641,683,853,863,947,2749,4297,4729 %N A172508 Prime numbers such that the differences between any pair of digits is prime. %C A172508 No further term between 4729 and 7368787 = A000040(500000). - _R. J. Mathar_, Feb 16 2010 %C A172508 As _Robert G. Wilson v_ points out, there are only 4 different single-digit primes, 2, 3, 5 and 7. Therefore the difference between any pair of a term cannot be zero; the terms can only have a maximum of 5 different digits. A full search covering this range shows that the sequence terminates with the 4729. - _R. J. Mathar_, Feb 25 2010 %p A172508 isA172508 := proc(n) local res,dgs,k,l ; dgs := convert(n,base,10) ; if nops(dgs) < 2 or not isprime(n) then return false; else for k from 1 to nops(dgs)-1 do for l from k+1 to nops(dgs) do if not isprime(abs( op(k,dgs)-op(l,dgs) )) then return false; end if; end do ; end do ; end if; return true; end proc: for i from 1 to 500000 do p := ithprime(i) : if isA172508(p) then printf("%d,\n",p) ; end if; end do: # _R. J. Mathar_, Feb 16 2010 %t A172508 Select[Prime[Range[638]],And@@PrimeQ[#[[1]]-#[[2]]&/@ Subsets[ IntegerDigits[ #],{2}]]&] (* _Harvey P. Dale_, Nov 29 2012 *) %K A172508 nonn,base,fini,full %O A172508 1,1 %A A172508 _Claudio Meller_, Feb 05 2010 %E A172508 Three more terms from _R. J. Mathar_ and _Robert G. Wilson v_, Feb 16 2010 %E A172508 Edited by _N. J. A. Sloane_, Feb 24 2010 %E A172508 Keywords:fini,full added by _Ray Chandler_ and _R. J. Mathar_, Feb 25 2010