A108049 Integers k such that 10^k + 43 is a prime number.

1, 5, 37, 253, 1129, 1441, 35393

Offset

1,2

Comments

a(8) > 10^5. - Robert Price, Nov 01 2013

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10043".

Links

Table of n, a(n) for n=1..7.

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

Index entries for primes involving repunits.

Example

k=5 is a term because 10^5 + 43 = 100043, which is prime.

Mathematica

Select[Range[2*10^3], PrimeQ[10^#+43]&] - Vladimir Joseph Stephan Orlovsky, Apr 29 2008

Prog

(PARI) is(n)=ispseudoprime(10^n+43) \\ Charles R Greathouse IV, Apr 28 2015

Crossrefs

Cf. A049054, A088274, A088275.

Sequence in context: A183385 A054417 A080507 * A121141 A331449 A220634

Adjacent sequences: A108046 A108047 A108048 * A108050 A108051 A108052

Keyword

nonn,more

Author

Julien Peter Benney (jpbenney(AT)ftml.net), Jun 01 2005

Extensions

a(7)=35393 from Robert Price, Mar 16 2010

Edited by Ray Chandler, Dec 23 2010

Status

approved