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A088623 Prime obtained as the concatenation 1 followed by the smallest power of n, or 0 if no such number exists. 2

%I #7 Mar 28 2015 22:12:29

%S 11,0,13,0,0,0,17,0,19,0,114641,0,113,0,0,0,1289,0,1361,0,

%T 11025506433613486607375777617584133309366191904729927960524981845743709132117581,

%U 0,1907846434775996175406740561329,0,0,0,127,0,1500246412961,0,131,0

%N Prime obtained as the concatenation 1 followed by the smallest power of n, or 0 if no such number exists.

%F a(2k)=a(5k)=0. - _Ray Chandler_, Oct 23 2003

%t f[n_] := Block[{k = 1}, While[ p = ToExpression["1" <> ToString[n^k]]; !PrimeQ[p], k++ ]; p]; g[n_] := If[ Mod[n, 10] == 1 || Mod[n, 10] == 3 || Mod[n, 10] == 7 || Mod[n, 10] == 9, f[n], 0]; Table[ g[n], {n, 1, 33}] (* _Robert G. Wilson v_, Oct 31 2003 *)

%Y Cf. A088622.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Oct 19 2003

%E Corrected and extended by _Ray Chandler_, Oct 23 2003

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Last modified July 17 18:40 EDT 2024. Contains 374377 sequences. (Running on oeis4.)