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A081092
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Primes having in binary representation a prime number of 1's.
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7
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3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 47, 59, 61, 67, 73, 79, 97, 103, 107, 109, 127, 131, 137, 151, 157, 167, 173, 179, 181, 191, 193, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 271, 283, 307, 313, 331, 367, 379, 397, 409, 419, 421, 431, 433, 439, 443
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| A049084(A000120(a(n))) > 0; A081091, A000215 and A081093 are subsequences.
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EXAMPLE
| 15-th prime = 47 = '101111' with five 1's, therefore 47 is a term.
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MATHEMATICA
| Clear[BinSumOddQ]; BinSumPrimeQ[a_]:=Module[{i, s=0}, s=0; For[i=1, i<=Length[IntegerDigits[a, 2]], s+=Extract[IntegerDigits[a, 2], i]; i++ ]; PrimeQ[s]]; lst={}; Do[p=Prime[n]; If[BinSumPrimeQ[p], AppendTo[lst, p]], {n, 4!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 06 2009]
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CROSSREFS
| Cf. A000040, A000120, A081093.
Sequence in context: A179479 A038604 A155026 * A163422 A155055 A030096
Adjacent sequences: A081089 A081090 A081091 * A081093 A081094 A081095
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KEYWORD
| nonn
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 05 2003
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