A227529 -id:A227529 - cp's OEIS frontend

A227530 Integer lengths of the n-th Copeland-Erdős prime (concatenation of the first n entries (digits) of A033308 is prime).

1, 2, 4, 11, 353, 355, 499, 1171, 1543, 5719, 11048, 68433, 97855, 292447

Offset: 1

Eric W. Weisstein, Jul 14 2013

a(15) > 300000. - Eric W. Weisstein (according to Mark Rodenkirch as of Dec 13 2015)
The larger of these are probable primes.
a(15) > 5*10^5 according to Mark Rodenkirch, June 2016. - M. F. Hasler, Apr 24 2017

Mark Rodenkirch (a.k.a. "rogue"), Copeland-Erdos Constant Primes, MersenneForum.org, June 2016.
Eric Weisstein's World of Mathematics, Copeland-Erdős Constant Digits

Cf. A227529 (primes corresponding to a(n) digits of the Copeland-Erdős constant), A019518, A069151.

Cf. also A033308 (Decimal expansion of Copeland-Erdős constant: concatenate primes).

a(12) = 68433 from Eric W. Weisstein, Aug 17 2013
a(13) = 97855 from Eric W. Weisstein, Oct 24 2015
a(14) = 292447 from Eric W. Weisstein, Dec 17 2015

A263959 Number of decimal digits in A069151(n).

Original entry on oeis.org

1, 2, 4, 355, 499, 1171, 1543, 5719

Offset: 1

Eric W. Weisstein, Oct 30 2015

Subset of A227530 (Copeland-Erdős constant primes) corresponding to concatenation of a full (non-truncated) final prime.

a(9) > 459970. - Eric W. Weisstein (according to Mark Rodenkirch as of Nov 21 2015)

Eric Weisstein's World of Mathematics, Consecutive Number Sequences
Eric Weisstein's World of Mathematics, Integer Sequence Primes
Eric Weisstein's World of Mathematics, Smarandache-Wellin Prime

Cf. A019518, A046035, A069151.
Cf. A227529 (Copeland-Erdős constant primes).
Cf. A227530 (decimal digits in n-th Copeland-Erdős constant prime).

Cases[FromDigits /@ Rest[FoldList[Join, {}, IntegerDigits[Prime[Range[10^3]]]]], p_?PrimeQ :> IntegerLength[p]]

p=""; for(n=1, 1e4, p=concat(p, prime(n)); if(ispseudoprime( eval(p)), print1(#Str(p)", "))) \\ Altug Alkan, Oct 30 2015

cp's OEIS Frontend

A227530 Integer lengths of the n-th Copeland-Erdős prime (concatenation of the first n entries (digits) of A033308 is prime).

Views

Author

Keywords

Comments

Links

Crossrefs

Extensions