A108112 Numbers k such that the string 3129k is prime.

29, 31, 37, 41, 43, 67, 71, 79, 89, 103, 121, 169, 193, 199, 209, 221, 223, 253, 257, 263, 271, 289, 323, 383, 391, 421, 431, 439, 443, 461, 463, 487, 517, 521, 523, 557, 559, 601, 611, 613, 617, 619, 629, 641, 677, 689, 691, 701, 733, 757, 769, 781, 787, 799, 803, 811, 821, 827, 839, 859

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

k=29 is in the sequence because 3129k = 312929 is prime.
k=103 is in the sequence because 3129k = 3129103 is prime.

Mathematica

Select[Range[1000], PrimeQ[3129*10^IntegerLength[#]+#]&] (* Harvey P. Dale, Jan 14 2015 *)

Prog

(Magma) [ n: n in [1..1750] | IsPrime(Seqint(Intseq(n) cat [9, 2, 1, 3])) ]; // Vincenzo Librandi, Feb 02 2011

Crossrefs

Sequence in context: A157498 A031062 A054056 * A007641 A050656 A050667

Adjacent sequences: A108109 A108110 A108111 * A108113 A108114 A108115

Keyword

nonn,base

Author

Parthasarathy Nambi, Jun 25 2005

Status

approved