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A281316
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Prime number p such that the decimal representation of its binary reflected Gray code is also a prime.
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2
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2, 3, 5, 13, 29, 41, 53, 73, 113, 149, 157, 173, 181, 197, 229, 233, 241, 293, 313, 317, 349, 373, 397, 541, 557, 653, 661, 673, 733, 757, 769, 773, 797, 809, 857, 953, 977, 1009, 1033, 1109, 1181, 1193, 1217, 1277, 1289, 1301, 1433, 1549, 1637, 1709, 1733, 1741, 1877, 1993, 2029, 2053, 2081
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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53 is in the sequence because the decimal representation of its binary reflected Gray code is 47 and both 53 and 47 are primes.
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PROG
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(Python)
from sympy import isprime
def G(n):
....return int(bin(n^(n/2))[2:], 2)
i=1
j=1
while j<=10000:
....if isprime(i)==True and isprime(G(i))==True:
........print str(j)+" "+str(i)
........j+=1
....i+=1
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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