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A143329
Primes in A143292.
1
3, 2, 7, 11, 19, 61, 47, 109, 73, 223, 211, 251, 239, 167, 151, 157, 137, 439, 421, 419, 499, 463, 331, 787, 827, 971, 991, 1009, 947, 911, 641, 647, 659, 701, 757, 613, 569, 521, 1549, 1663, 1747, 1789, 1697, 1667, 1933, 1951, 1877, 1291, 1367, 1531, 1447, 1451
OFFSET
1,1
COMMENTS
Primes that are Gray codes of other "source" primes, ordered along increasing source primes, i.e., in the order of appearance in A143292.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Kevin Ryde, A143329 gray code primes sample values, SeqFan Mailing list Apr 19 2012
MATHEMATICA
GrayCode[n_] := BitXor[n, Floor[n/2]]; Select[ GrayCode@ Prime@ Range@ 275, PrimeQ] (* Robert G. Wilson v, Mar 11 2015 *)
PROG
(Magma)
I2B:=func<i | [b eq 1: b in IntegerToSequence(i, 2)]>;
B2I:=func<s | SequenceToInteger([b select 1 else 0: b in s], 2)>;
[g: n in [1..999] | IsPrime(g) where g is B2I(Xor(I2B(i), I2B(i div 2)cat[false])) where i is NthPrime(n)]; // Jason Kimberley, Apr 19 2012
(PARI) forprime(p=2, 3e6, if(isprime(t=bitxor(p, p>>1)), print1(t", "))) \\ Charles R Greathouse IV, Apr 19 2012
CROSSREFS
Sequence in context: A174330 A099329 A182871 * A365227 A053440 A329724
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Jason Kimberley corrected all terms after a(38) at the suggestion of Kevin Ryde, Apr 19 2012
STATUS
approved