A282690 a(n) is the smallest number m, such that m+n is the next prime and m-n is the previous prime.

4, 5, 26, 93, 144, 53, 120, 1839, 532, 897, 1140, 211, 2490, 2985, 4312, 5607, 1344, 9569, 30612, 19353, 16162, 15705, 81486, 16787, 31932, 19635, 35644, 82101, 44322, 43361, 34092, 89721, 162176, 134547, 173394, 31433, 404634, 212739, 188068, 542643, 265662

Offset: 1

Author

Daniel Suteu, Feb 20 2017

Keywords

• nonn

Examples

			For n = 6, a(6) = 53, because the next prime after 53 is 59 and the previous prime before 53 is 47, where both have an equal distance of 6 from 53, which is the smallest number with this property.
		

Links

• Daniel Suteu, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A087378, A087711, A282687.

Programs

Mathematica

Table[k = 1; While[Nand[k - n == NextPrime[k, -1], k + n == NextPrime@ k], k++]; k, {n, 41}] (* Michael De Vlieger, Feb 20 2017 *)

Perl

use ntheory qw(:all);
for (my $k = 1 ; ; ++$k) {
    for (my $n = 1 ; ; ++$n) {
        my $p = prev_prime($n) || next;
        my $q = next_prime($n);
        if ($n-$p == $k and $q-$n == $k) {
            printf("%s %s\n", $k, $n);
            last;
        }
    }
}