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A172998 Numbers n such that 10^4n + 10^3n - 10^n - 3 is prime. 1
1, 2, 3, 4, 372 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Corresponds to the numbers 10987, 100999897, 1000999998997, 10000999999989997, ...

LINKS

Table of n, a(n) for n=1..5.

MATHEMATICA

fQ[n_] := PrimeQ[10^(4 n) + 10^(3 n) - 10^n - 3]; k = 1; lst = {}; While[k < 3300, If[ fQ@k, AppendTo[lst, k]]; k++ ]; lst (* Robert G. Wilson v, Feb 15 2010 *)

PROG

(PARI) is(n)=ispseudoprime(10^4*n+10^3*n-10^n-3) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A244548 A004877 A116022 * A004888 A062928 A004899

Adjacent sequences:  A172995 A172996 A172997 * A172999 A173000 A173001

KEYWORD

nonn

AUTHOR

James G. Merickel, Feb 07 2010

STATUS

approved

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Last modified August 3 05:55 EDT 2020. Contains 336197 sequences. (Running on oeis4.)