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A020458 Primes that contain digits 2 and 3 only. 52

%I

%S 2,3,23,223,233,2333,3323,23333,32233,32323,33223,222323,232333,

%T 233323,323233,323333,333233,333323,2222333,2223233,2232323,2233223,

%U 2332333,2333323,3222223,3223223,3223333,3233323,3233333,3332233,3333233

%N Primes that contain digits 2 and 3 only.

%H Charles R Greathouse IV, <a href="/A020458/b020458.txt">Table of n, a(n) for n = 1..10000</a>

%t Flatten[Table[Select[FromDigits/@Tuples[{2,3},n],PrimeQ],{n,7}]] (* _Harvey P. Dale_, Jul 13 2012 *)

%o (PARI) go(n)=my(v=List([2]),x,t); for(d=1,n, x=10^d\9*2; forstep(i=1,2^d-1,2, if(ispseudoprime(t=x+fromdigits(binary(i))), listput(v,t)))); Vec(v) \\ _Charles R Greathouse IV_, Sep 14 2015

%Y Cf. A139067, A139069, A032810, A020463.

%K nonn,base

%O 1,1

%A _David W. Wilson_

%E Edited by _N. J. A. Sloane_, Jul 27 2008 at the suggestion of Dmitry Kamenetsky.

%E Edited by _Charles R Greathouse IV_, Mar 17 2010

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Last modified November 17 11:02 EST 2019. Contains 329226 sequences. (Running on oeis4.)