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A282690 a(n) = smallest number m, such that m+n is the next prime and m-n is the previous prime. 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

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.

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 *)

PROG

(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;

        }

    }

}

CROSSREFS

Cf. A087378, A087711, A282687.

Sequence in context: A144053 A084465 A056200 * A282687 A153429 A270217

Adjacent sequences:  A282687 A282688 A282689 * A282691 A282692 A282693

KEYWORD

nonn

AUTHOR

Daniel Suteu, Feb 20 2017

STATUS

approved

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Last modified October 16 20:34 EDT 2018. Contains 316275 sequences. (Running on oeis4.)