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 A004676 Primes written in base 2. 80
 10, 11, 101, 111, 1011, 1101, 10001, 10011, 10111, 11101, 11111, 100101, 101001, 101011, 101111, 110101, 111011, 111101, 1000011, 1000111, 1001001, 1001111, 1010011, 1011001, 1100001, 1100101, 1100111, 1101011, 1101101, 1110001, 1111111, 10000011, 10001001 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 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 REFERENCES J.-P. Allouche and J. Shallit, Automatic Sequences, Cambridge Univ. Press, 2003, p. 3. LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 Chris Caldwell, The prime pages, The first 1000 primes. FORMULA a(n) = A007088(A000040(n)). - R. J. Mathar, Jun 03 2011 MATHEMATICA FromDigits /@ IntegerDigits[ Prime[ Range[31]], 2] (* Robert G. Wilson v, Jun 30 2005 *) PROG (Haskell) a004676 = a007088 . a000040  -- Reinhard Zumkeller, Aug 06 2012 (PARI) a(n)=subst(Pol(binary(prime(n))), 'x, 10) \\ Charles R Greathouse IV, Mar 20 2013 CROSSREFS Cf. A019434 Fermat primes (base 10), A000668 Mersenne primes (base 10). Cf. A174332, A208238, A208241. Sequence in context: A230297 A086084 A206073 * A303593 A124387 A171796 Adjacent sequences:  A004673 A004674 A004675 * A004677 A004678 A004679 KEYWORD nonn,easy,base AUTHOR STATUS approved

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Last modified April 19 20:37 EDT 2021. Contains 343117 sequences. (Running on oeis4.)