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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

%I #3 Oct 15 2013 22:32:12

%S 2,4,52,61,43,49,29,8,223,53,83,59,25,568,47,221,229,1286,427,629,637,

%T 46,109,652,458,925,1438,86,674,535

%N 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.

%e 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.

%Y Cf. A085324.

%K base,nonn

%O 1,1

%A _Labos Elemer_, Jul 02 2003

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Last modified February 28 01:44 EST 2024. Contains 370379 sequences. (Running on oeis4.)