A275629 The least odd prime leaving a prime remainder when divided by each of the first n odd primes.
5, 17, 17, 47, 863, 863, 887, 887, 887, 887, 133877, 858707, 886013, 11891003, 11891003, 324840323, 1364103977, 7151489963, 7151489963, 10402068437, 10402068437, 875858298023, 7859437730303, 7859437730303, 10784807012723, 304858842631367, 1939577853386297, 4237718864973557
Offset: 1
Keywords
Examples
47 mod 3,5,7,11 is 2,2,5,3, which are all primes.
Links
- Bert Dobbelaere, Table of n, a(n) for n = 1..36
- J. M. Bergot (Proposer), The least odd prime leaving prime remainder when divided by the first nn odd primes, Mathematics Stack Exchange, 2016.
Programs
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Perl
use ntheory ":all"; sub a275629 { my($n)=@; my $it=prime_iterator(3); my @fnp = map { $it->() } 1..$n; while (1) { $p=$it->(); return $p if vecall {is_prime($p%$)} @fnp; } } say a275629($) for 1..20; # _Dana Jacobsen, Aug 09 2016
Extensions
Corrected and extended by Dana Jacobsen, Aug 09 2016
a(22) onwards from Bert Dobbelaere, Sep 13 2019