A103888 Numbers k such that the string 100k001 is prime.

3, 8, 12, 21, 23, 38, 42, 45, 48, 51, 54, 56, 59, 69, 72, 83, 86, 92, 93, 105, 111, 113, 131, 135, 137, 159, 161, 162, 174, 176, 183, 203, 207, 209, 210, 228, 230, 237, 245, 246, 249, 260, 264, 267, 273, 287, 300, 324, 327, 330, 336, 341, 345, 362, 386, 390, 396

Offset

1,1

Links

Table of n, a(n) for n=1..57.

Example

93 is a term, as 10093001 is prime.

Mathematica

Select[Range[400], PrimeQ[FromDigits[Flatten[Prepend[IntegerDigits[1000#+1], {1, 0, 0}]]]]&] (* James C. McMahon, Jan 17 2024 *)

Crossrefs

Cf. A099678.

Sequence in context: A287081 A352814 A294482 * A014255 A350221 A370755

Adjacent sequences: A103885 A103886 A103887 * A103889 A103890 A103891

Keyword

base,nonn,less

Author

Parthasarathy Nambi, Mar 30 2005

Extensions

More terms from David Wasserman, Apr 24 2008

Status

approved