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A092621
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Primes with exactly one prime digit.
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16
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2, 3, 5, 7, 13, 17, 29, 31, 43, 47, 59, 67, 71, 79, 83, 97, 103, 107, 113, 131, 139, 151, 163, 167, 179, 193, 197, 211, 241, 269, 281, 311, 349, 389, 421, 431, 439, 443, 463, 467, 479, 487, 509, 541, 569, 599, 607, 613, 617, 631, 643, 647, 659, 683, 701, 709
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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FORMULA
| a(n) >> n^1.28 because of the digit restriction
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EXAMPLE
| 13 is prime and it has one prime digit, 3;
103 is prime and it has one prime digit, 3.
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MAPLE
| 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_prn:=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) = 1) then ans:=[ op(ans), i ]: tren:=tren+1; fi od; RETURN(ans) end: ts_pr_prn(1000);
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MATHEMATICA
| podQ[n_]:=(1==Length@Select[IntegerDigits[n], PrimeQ]); Select[Prime[Range[250]], podQ](* Zak Seidov *)
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PROG
| (Sage) A092621 = list(p for p in primes(1000) if len([d for d in p.digits() if is_prime(d)]) == 1)
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CROSSREFS
| Cf. A034844.
Sequence in context: A125772 A001000 A094947 * A188809 A152449 A048975
Adjacent sequences: A092618 A092619 A092620 * A092622 A092623 A092624
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KEYWORD
| nonn,base
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AUTHOR
| Jani Melik (jani_melik(AT)hotmail.com), Apr 11 2004
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