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Search: id:A064489
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| A064489 |
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Let p = prime(n); a(n) = smallest m such that prime(m) has p digits. |
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+0
3
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| 5, 26, 1230, 78499, 455052512, 37607912019, 279238341033926, 24739954287740861, 201467286689315906291
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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n=5; prime(5)=11 and 11 is the first prime with a prime number of decimal digits.
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PROGRAM
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(PARI) l(n)=ln=0; while(n, n=floor(n/10); ln++); return(ln); a=0; for(n=1, 10^6, x=l(prime(n)); if(isprime(x), b=x; if(b>a, a=b; print(n))))
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CROSSREFS
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Cf. A064490.
a(n) = 1 + A006880(A000040(n-1)).
Sequence in context: A015490 A118366 A132509 this_sequence A081089 A118391 A097088
Adjacent sequences: A064486 A064487 A064488 this_sequence A064490 A064491 A064492
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KEYWORD
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base,easy,nonn
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AUTHOR
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Jason Earls (zevi_35711(AT)yahoo.com), Oct 04 2001
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Jul 22 2002
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