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A160337 1 plus primes using only digits {0, 1, 2, 3, 5, 7}. 2

%I

%S 1,2,3,5,7,11,13,17,23,31,37,53,71,73,101,103,107,113,127,131,137,151,

%T 157,173,211,223,227,233,251,257,271,277,307,311,313,317,331,337,353,

%U 373,503,521,523,557,571,577,701,727,733,751,757,773,1013,1021,1031

%N 1 plus primes using only digits {0, 1, 2, 3, 5, 7}.

%H Alois P. Heinz, <a href="/A160337/b160337.txt">Table of n, a(n) for n = 1..10000</a>

%o (C++)

%o #include <iostream>

%o using namespace std;

%o bool isPrime(long n)

%o {

%o if(n==0) return true;

%o for(long i = 2; i<=n/2; i++) { if(n%i == 0) return false; }

%o return true;

%o }

%o bool checkdigit(long n)

%o {

%o long no = n;

%o while(no>0)

%o {

%o long digit = no%10;

%o if(digit==0) return false;

%o else { if(!isPrime (digit)) return false; }

%o no = no/10;

%o }

%o return true;

%o }

%o int main()

%o {

%o long limit = 1000000000; int count =0;

%o for(long i=1; i<=limit; i++)

%o {

%o if(isPrime(i) && checkdigit(i))

%o { count++; cout<<i<<endl; }

%o if(count == 100) { return 0; }

%o }

%o return 0;

%o }

%o (Python)

%o from sympy import isprime

%o def ok(n): return n == 1 or (set(str(n)) <= set("012357") and isprime(n))

%o print([m for m in range(1032) if ok(m)]) # _Michael S. Branicky_, Jan 25 2021

%Y Cf. A012884, A143390.

%K nonn,base

%O 1,2

%A Mohit Singh Kanwal (mohit_kanwal(AT)hotmail.com), May 10 2009

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Last modified August 17 02:42 EDT 2022. Contains 356180 sequences. (Running on oeis4.)