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%I #37 Oct 26 2023 01:01:16
%S 10,11,101,111,1011,1101,10001,10011,10111,11101,11111,100101,101001,
%T 101011,101111,110101,111011,111101,1000011,1000111,1001001,1001111,
%U 1010011,1011001,1100001,1100101,1100111,1101011,1101101,1110001,1111111,10000011,10001001
%N Primes written in base 2.
%C The only primes of binary weight 2 are the Fermat primes (only five are known: 11, 101, 10001, 100000001, 10000000000000001); the repunits base 2 are the Mersenne primes. - _Daniel Forgues_, Nov 07 2011
%D J.-P. Allouche and J. Shallit, Automatic Sequences, Cambridge Univ. Press, 2003, p. 3.
%H T. D. Noe, <a href="/A004676/b004676.txt">Table of n, a(n) for n = 1..1000</a>
%H Chris Caldwell, The prime pages, <a href="http://www.utm.edu/research/primes/lists/small/1000.txt">The first 1000 primes</a>.
%F a(n) = A007088(A000040(n)). - _R. J. Mathar_, Jun 03 2011
%t FromDigits /@ IntegerDigits[ Prime[ Range[31]], 2] (* _Robert G. Wilson v_, Jun 30 2005 *)
%o (Haskell)
%o a004676 = a007088 . a000040 -- _Reinhard Zumkeller_, Aug 06 2012
%o (PARI) a(n)=subst(Pol(binary(prime(n))), 'x, 10) \\ _Charles R Greathouse IV_, Mar 20 2013
%Y Cf. A019434 Fermat primes (base 10), A000668 Mersenne primes (base 10).
%Y Cf. A174332, A208238, A208241.
%K nonn,easy,base
%O 1,1
%A _N. J. A. Sloane_
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