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A103408 Numbers n such that n2101 is prime. 2
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified January 26 21:14 EST 2022. Contains 350600 sequences. (Running on oeis4.)