cp's OEIS Frontend

A092628 Primes with exactly three nonprime digits.

%I A092628 #8 Nov 21 2013 12:48:17
%S A092628 101,109,149,181,191,199,401,409,419,449,461,491,499,601,619,641,661,
%T A092628 691,809,811,881,911,919,941,991,1013,1021,1031,1039,1051,1063,1087,
%U A092628 1093,1097,1103,1117,1129,1151,1163,1171,1187,1193,1201,1249,1289,1291
%N A092628 Primes with exactly three nonprime digits.
%H A092628 Harvey P. Dale, <a href="/A092628/b092628.txt">Table of n, a(n) for n = 1..1000</a>
%e A092628 101 is prime and it has three nonprime digits, 0 and twice 1;
%e A092628 4261 is prime and it has three nonprime digits, 1, 4 and 6.
%p A092628 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_stnepf:=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))='false') then stpf:=stpf+1; # number of nonprime digits fi od; RETURN(stpf) end: ts_pr_neprnt:=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_stnepf(i) = 3) then ans:=[ op(ans), i ]: tren:=tren+1; fi od; RETURN(ans) end: ts_pr_neprnt(5000);
%t A092628 dgQ[n_]:=Count[IntegerDigits[n],_?(!PrimeQ[#]&)]==3; Select[Prime[ Range[300]], dgQ] (* _Harvey P. Dale_, Oct 11 2011 *)
%Y A092628 Cf. A019546, A034844.
%K A092628 nonn,base
%O A092628 1,1
%A A092628 _Jani Melik_, Apr 11 2004