A103408 Numbers n such that n2101 is prime.

1, 4, 7, 10, 18, 24, 25, 28, 31, 34, 39, 42, 48, 51, 63, 70, 73, 76, 79, 81, 85, 93, 94, 100, 126, 139, 148, 150, 156, 157, 160, 163, 168, 174, 177, 184, 186, 199, 202, 207, 219, 232, 234, 235, 237, 265, 268, 277, 300, 301, 307, 309, 315, 316, 321, 322, 328, 343, 354, 358, 364, 366

Offset

1,2

Links

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

Example

If n=1, then n2101 = 12101 (prime).
If n=31, then n2101 = 312101 (prime).
If n=63, then n2101 = 632101 (prime).

Mathematica

Select[Range[400], PrimeQ[10000#+2101]&] (* Harvey P. Dale, Jul 20 2015 *)

Prog

(Magma) [ n: n in [1..700] | IsPrime(Seqint([1, 0, 1, 2] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 03 2011
(PARI) is(n)=isprime(10000*n+2101) \\ Charles R Greathouse IV, Jun 06 2017

Crossrefs

Cf. A103118, A102624.

Sequence in context: A071415 A310718 A310719 * A208717 A208773 A088408

Adjacent sequences: A103405 A103406 A103407 * A103409 A103410 A103411

Keyword

base,nonn,easy

Author

Parthasarathy Nambi, Mar 20 2005

Status

approved