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A095072
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Primes in whose binary expansion the number of 0-bits is one more than the number of 1-bits.
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4
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17, 67, 73, 97, 263, 269, 277, 281, 293, 337, 353, 389, 401, 449, 1039, 1051, 1063, 1069, 1109, 1123, 1129, 1163, 1171, 1187, 1193, 1201, 1249, 1291, 1301, 1321, 1361, 1543, 1549, 1571, 1609, 1667, 1669, 1697, 1801, 4127, 4157, 4211, 4217
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internal format)
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OFFSET
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1,1
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COMMENTS
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A010051(a(n) = 1 and A037861(a(n)) = 1. - Reinhard Zumkeller, Mar 31 2015
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LINKS
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Indranil Ghosh, Table of n, a(n) for n = 1..20000 (terms 1..1000 from Reinhard Zumkeller)
A. Karttunen and J. Moyer, C-program for computing the initial terms of this sequence
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EXAMPLE
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97 is in the sequence because 97 is a prime and 97_10 = 1100001_2. The number of 0's in 1100001 is 4 and the number of 1's is 3. - Indranil Ghosh, Jan 31 2017
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MATHEMATICA
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Select[Prime[Range[500]], Differences[DigitCount[#, 2]] == {1} &]
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PROG
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(PARI) isA095072(n)=my(v=binary(n)); #v==2*sum(i=1, #v, v[i])+1&&isprime(n)
(PARI) forprime(p=2, 4250, v=binary(p); s=0; for(k=1, #v, s+=if(v[k]==0, +1, -1)); if(s==1, print1(p, ", ")))
(Haskell)
a095072 n = a095072_list !! (n-1)
a095072_list = filter ((== 1) . a010051' . fromIntegral) a031444_list
-- Reinhard Zumkeller, Mar 31 2015
(Python)
#Program to generate the b-file
from sympy import isprime
i=1
j=1
while j<=200:
if isprime(i) and bin(i)[2:].count("0")-bin(i)[2:].count("1")==1:
print(str(j)+" "+str(i))
j+=1
i+=1 # Indranil Ghosh, Jan 31 2017
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CROSSREFS
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Intersection of A000040 and A031444. Subset of A095071.
Cf. A095052.
Cf. A010051, A037861.
Sequence in context: A157474 A024215 A095071 * A180529 A214032 A039452
Adjacent sequences: A095069 A095070 A095071 * A095073 A095074 A095075
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KEYWORD
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nonn,base,easy
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AUTHOR
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Antti Karttunen, Jun 01 2004
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STATUS
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approved
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