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A121267 Number of decimal digits in A047777(n). 3
1, 5, 1, 3, 1, 2, 1, 4, 3057, 2, 3, 14650, 4, 2, 46, 4 (list; graph; refs; listen; history; text; internal format)



Not equal to the first differences of A053013 (which is based on a different variant of A047777).

"A new visitor to an old problem! Jens Kruse Andersen confirmed the primality of Nash's 3057-digit prime using PRIMO." - Carlos Rivera, Sep 2002.


Table of n, a(n) for n=1..16.

Carlos Rivera, Problem 18. Pi as a concatenation of the smallest contiguous different primes, The Prime Puzzles & Problems Connection.


(PARI) default(realprecision, 5000); c=Pi/10; u=[]; for(k=1, 9e9, ispseudoprime(c\.1^k) & !setsearch(u, c\.1^k) & (u=setunion(u, Set(c\.1^k))) & !print1(k, ", ") & k=0*c=frac(c*10^k)) \\ - M. F. Hasler, Sep 15 2013


Cf. A047777, A053013.

Sequence in context: A134568 A198798 A229181 * A111740 A327921 A155059

Adjacent sequences:  A121264 A121265 A121266 * A121268 A121269 A121270




Robert G. Wilson v, Aug 23 2006


The old values a(10) onwards were incorrect, as discovered by M. F. Hasler, Aug 31 2013. The old values, the b-file and the Mathematica program have been deleted. - N. J. A. Sloane, Sep 01 2013



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Last modified December 7 20:40 EST 2021. Contains 349589 sequences. (Running on oeis4.)