A121267 Number of decimal digits in A047777(n).

1, 5, 1, 3, 1, 2, 1, 4, 3057, 2, 3, 14650, 4, 2, 46, 4

Offset: 1

Author

Robert G. Wilson v, Aug 23 2006

Keywords

• nonn
• base
• more
• hard

Comments

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

If it exists, then a(17) > 50000. - Lucas A. Brown, Jul 04 2024

Links

• Lucas A. Brown, Python program.
• Carlos Rivera, Problem 18. Pi as a concatenation of the smallest contiguous different primes, The Prime Puzzles & Problems Connection.

Crossrefs

Cf. A047777, A053013.

Programs

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

Extensions

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