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

11, 0, 13, 0, 0, 0, 17, 0, 19, 0, 114641, 0, 113, 0, 0, 0, 1289, 0, 1361, 0, 11025506433613486607375777617584133309366191904729927960524981845743709132117581, 0, 1907846434775996175406740561329, 0, 0, 0, 127, 0, 1500246412961, 0, 131, 0

Offset: 1

Author

Amarnath Murthy, Oct 19 2003

Keywords

• base
• nonn

Crossrefs

Cf. A088622.

Programs

Mathematica

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 *)

Formula

a(2k)=a(5k)=0. - Ray Chandler, Oct 23 2003

Extensions

Corrected and extended by Ray Chandler, Oct 23 2003