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A104387
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Larger of two successive primes the average of which is a repdigit.
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3
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5, 7, 11, 101, 113, 4447, 111111113, 555555555559, 10000000000000061, 111111111111111131, 444444444444444469, 555555555555555555619, 777777777777777777777787, 333333333333333333333333333333373
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Lesser primes A104388, repdigits A104389. What is the next term?
The next term is 444444444444444444444444444444444497. The first term with more than 100 digits is a(22) which has 109 digits. [From Harvey P. Dale, June 28 2011]
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FORMULA
| a(n)=p[A104386(n)+1]
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MATHEMATICA
| Union[Flatten[Table[NextPrime/@Select[FromDigits/@Table[PadLeft[{i}, n, i], {n, 45}], Mean[{NextPrime[#], NextPrime[#, -1]}]==#&], {i, 9}]]] (* From Harvey P. Dale, Jun 28 2011 *)
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CROSSREFS
| Cf. A054268, A104386, A104388, A104389.
Sequence in context: A091509 A027728 A086140 * A133761 A057659 A098040
Adjacent sequences: A104384 A104385 A104386 * A104388 A104389 A104390
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KEYWORD
| nonn,base
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Mar 04 2005
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EXTENSIONS
| More terms from Giovanni Resta (g.resta(AT)iit.cnr.it), Apr 05 2006
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