The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A088622 Smallest prime obtained as the concatenation of a power of n followed by a 1, or 0 if no such number exists. 5
 11, 41, 31, 41, 251, 61, 71, 641, 811, 101, 259374246011, 0, 131, 75295361, 151, 40961 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(12) = 0. Subsidiary sequence: n such that 10*n^k +1 is composite for all k >0 (indices of zero entries in this sequence): see A088783. a(17) is too large to display here. After a(17) the sequence continues: 181, 191, 4001, 211, 1368800680154120519681, 0, 241, 251, 6761, 271, 281, 7072811, 9001, 311, 0, 331, 0, 12251, 466561, 13691, 20851361, 23134411, 401 LINKS Table of n, a(n) for n=1..16. MATHEMATICA f[n_] := Block[{k = 1}, While[ !PrimeQ[10*n^k + 1] && k != 1500, k++ ]; If[k == 1500, 0, 10*n^k + 1]]; Table[ f[n], {n, 1, 50}] (* Robert G. Wilson v, Oct 25 2003 *) CROSSREFS Cf. A088623, A088782, A088783. Sequence in context: A073626 A065144 A089348 * A121171 A239790 A065079 Adjacent sequences: A088619 A088620 A088621 * A088623 A088624 A088625 KEYWORD base,nonn AUTHOR Amarnath Murthy, Oct 19 2003 EXTENSIONS Next term is too large to include. - Ray Chandler, Oct 23 2003 Extended by Robert G. Wilson v, Oct 25 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 23 21:14 EDT 2024. Contains 372765 sequences. (Running on oeis4.)