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A144753
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A positive integer n is included if n is a palindrome in binary and n has a prime number of 1's in its binary representation.
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1
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3, 5, 7, 9, 17, 21, 31, 33, 65, 73, 93, 107, 127, 129, 257, 273, 313, 341, 381, 403, 443, 471, 513, 1025, 1057, 1137, 1193, 1273, 1317, 1397, 1453, 1571, 1651, 1707, 1831, 2047, 2049, 4097, 4161, 4321, 4433, 4593, 4681, 4841, 4953, 5189, 5349, 5461, 5709
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Each term of this sequence is in both sequence A006995 and sequence A052294.
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EXAMPLE
| 21 in binary is 10101. This binary representation is a palindrome. And it contains three 1's and three is a prime. So 21 is included in the sequence.
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MATHEMATICA
| okQ[n_] := Module[{idn2 = IntegerDigits[n, 2]}, (idn2 == Reverse[idn2]) && PrimeQ[First[DigitCount[n, 2]]]]; Select[Range[10000], okQ] [From Harvey P. Dale (hpd1(AT)nyu.edu), Sep 23 2008]
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CROSSREFS
| A144752, A006995, A052294
Sequence in context: A146556 A084229 A191356 * A057482 A114136 A025072
Adjacent sequences: A144750 A144751 A144752 * A144754 A144755 A144756
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KEYWORD
| base,nonn
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AUTHOR
| Leroy Quet Sep 20 2008
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EXTENSIONS
| Additional terms provided; Mathematica program provided Harvey P. Dale (hpd1(AT)nyu.edu), Sep 23 2008
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