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A178430 Numbers n such that 10^n - 53 is prime. 0
2, 3, 11, 15, 23, 29, 44, 71, 83, 95, 159, 383, 404, 548, 633, 6409, 8793, 24146, 25727, 64436, 74335, 76875 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term, if it exists, is > 100000.

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99947".

LINKS

Table of n, a(n) for n=1..22.

Makoto Kamada, List of near-repdigit-related prime numbers.

Index entries for primes involving repunits.

EXAMPLE

10^3 - 53 = 947 which is a prime number.

MATHEMATICA

m=1000; For[n=1, n<m, If[PrimeQ[10^n-53], Print[n]]; n++ ]

PROG

(PARI) is(n)=ispseudoprime(10^n-53) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A108330, A108328.

Sequence in context: A041637 A042235 A050587 * A066687 A144979 A194558

Adjacent sequences:  A178427 A178428 A178429 * A178431 A178432 A178433

KEYWORD

more,nonn

AUTHOR

Robert Price, Dec 21 2010

EXTENSIONS

Corrected terms a(17) and a(18) by Robert Price, Dec 24 2010

a(20-22)=64436,74335,76875 from Robert Price, May 29 2011

STATUS

approved

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Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.