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 A092623 #9 Nov 21 2013 12:48:17 %S A092623 223,227,233,257,277,337,353,373,523,557,577,727,733,757,773,1223, %T A092623 1237,1277,1327,1373,1523,1553,1723,1733,1753,1777,2027,2053,2137, %U A092623 2153,2203,2207,2213,2221,2239,2243,2251,2267,2287,2293,2297,2339,2347,2351,2371 %N A092623 Primes with exactly three prime digits. %F A092623 a(n) >> x^1.285 %e A092623 223 is prime and it has three prime digits 2,2,3; %e A092623 1237 is prime and it has three prime digits 2,3,7; %p A092623 stev_sez:=proc(n) local i, tren, st, ans, anstren; ans:=[ ]: anstren:=[ ]: tren:=n: for i while (tren>0) do st:=round( 10*frac(tren/10) ): ans:=[ op(ans), st ]: tren:=trunc(tren/10): end do; for i from nops(ans) to 1 by -1 do anstren:=[ op(anstren), op(i,ans) ]; od; RETURN(anstren); end: ts_stpf:=proc(n) local i, stpf, ans; ans:=stev_sez(n): stpf:=0: for i from 1 to nops(ans) do if (isprime(op(i,ans))='true') then stpf:=stpf+1; # number of prime digits fi od; RETURN(stpf) end: ts_pr_prnt:=proc(n) local i, stpf, ans, ans1, tren; ans:=[ ]: stpf:=0: tren:=1: for i from 1 to n do if ( isprime(i)='true' and ts_stpf(i) = 3) then ans:=[ op(ans), i ]: tren:=tren+1; fi od; RETURN(ans) end: ts_pr_prnt(5000); %t A092623 Select[Prime[Range[400]],Count[IntegerDigits[#],_?PrimeQ]==3&] (* _Harvey P. Dale_, Dec 27 2011 *) %Y A092623 Cf. A034844, A019546. %K A092623 nonn,base %O A092623 1,1 %A A092623 _Jani Melik_, Apr 11 2004