A085325 a(n) is the least number such that the minimal exponent for which rev[a(n)^n]=prime holds is n. Thus rev[a(n)^k] is composite for k=1,..n.

2, 4, 52, 61, 43, 49, 29, 8, 223, 53, 83, 59, 25, 568, 47, 221, 229, 1286, 427, 629, 637, 46, 109, 652, 458, 925, 1438, 86, 674, 535

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Example

n=10, a(10)=53: This means that rev[53^10]=940315563074788471 is prime, but rev[53^k] is composite for k=1,...,9. Also, rev[a^10] for a<a(n)=53 is not prime. However a>53 is possible like e.g rev[103^10] is prime; 10 as the least exponent belongs to several bases of which a(10)=53 is the smallest one.

Crossrefs

Cf. A085324.

Sequence in context: A277034 A156498 A211169 * A082661 A205616 A115587

Adjacent sequences: A085322 A085323 A085324 * A085326 A085327 A085328

Keyword

base,nonn

Author

Labos Elemer, Jul 02 2003

Status

approved