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Search: id:A064779
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| A064779 |
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Primes such that the sum of their digits, and the sum of the reciprocals of their digits is also prime. |
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+0
1
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| 11, 2441, 4241, 4421, 12163, 12613, 13313, 13331, 16231, 16363, 16633, 21163, 21613, 26113, 31663, 32233, 32323, 32611, 33113, 33223, 33311, 48281, 48821, 61231, 61363, 62131, 62311, 63211, 63361, 88241
(list; graph; listen)
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OFFSET
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1,1
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MATHEMATICA
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f[ n_ ] := 1/n a[ n_ ] := Apply[ Plus, Map[ f, IntegerDigits[ n ] ] ] b[ n_ ] := Apply[ Plus, IntegerDigits[ n ] ] Select[ Range[ 100000 ], FreeQ[ IntegerDigits[ # ], 0 ] && PrimeQ[ a[ # ] ] && PrimeQ[ b[ # ] ] && PrimeQ[ # ] & ]
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CROSSREFS
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Cf. A034708.
Sequence in context: A078271 A087403 A085878 this_sequence A138075 A134806 A024152
Adjacent sequences: A064776 A064777 A064778 this_sequence A064780 A064781 A064782
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KEYWORD
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base,nonn
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AUTHOR
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Santi Spadaro (spados(AT)katamail.com), Oct 19 2001
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