A110600 Minimal set of prime-strings in base 12 in the sense of A071062.

2, 3, 5, 7, 11, 13, 73, 97, 109, 577, 1489, 7537, 17401, 226201, 1097113, 32555521, 388177921

Offset

1,1

Comments

Maple worksheet available upon request. Here is the minimal set in base 12 where X is 10 and E is 11. 2, 3, 5, 7, E, 11, 61, 81, 91, 401, X41, 4441, X0X1, XXXX1, 44XXX1, XXX0001, XX000001. This minimal set demonstrates the elegance of base 12 generally since you can mentally follow the process of elimination, all primes after E end in the neutral digit 1 and the last two entries only contain X, 0 and 1. There are no primes of the form X0...01 since the sum of its digits is E and hence it is divisible by E.

The smallest prime found to date that satisfies all patterns in the minimal set is 1234456789X04XXX00E0001 (656969693573113867991809 in base 10). [Walter Kehowski, May 18 2012]

Links

Table of n, a(n) for n=1..17.

Example

a(10)=401 since no earlier prime in the list contained the pattern "*4*0*1*" where "*" stands for zero or more digits. The list can be manually constructed using a sieve-like process: eliminate all subsequent primes of the form "*4*0*1*" from the list of all primes. Assuming all previous elements have also been similarly determined, the next remaining prime should be X41.

Crossrefs

Cf. A071062, A071070.

Sequence in context: A037174 A238851 A037949 * A029979 A029981 A029982

Adjacent sequences: A110597 A110598 A110599 * A110601 A110602 A110603

Keyword

nonn,base

Author

Walter Kehowski, Sep 14 2005

Status

approved