A262936 Lesser of lonely twin primes pairs with increasing distance to nearest prime.

3, 5, 11, 29, 419, 521, 1931, 6449, 10007, 28349, 107507, 173429, 569321, 913637, 1349531, 3593201, 18286391, 80528741, 83528411, 591792347, 1971409091, 2061246347, 8579208791, 13861166687, 15250041281, 27034148369, 27066034997, 54125499299, 315361055237

Offset

1,1

Links

Dmitry Petukhov, Table of n, a(n) for n = 1..40

Formula

a(n) = p(i) if ( (p(i+1) = p(i)+2) AND (min(p(i+2)-p(i+1), p(i)-p(i-1)) > a(n-1)) ), where a(0) = 0, p(k) = prime(k) = A000040(k).

Example

(3,5) is a twin primes pair, min(7-5, 3-2)=1, therefore a(1)=3.
(5,7) is a twin primes pair, min(11-7, 5-3)=2>1, therefore a(2)=5.
(11,13) is a twin primes pair, min(17-13, 11-7)=4>2, therefore a(3)=11.

Prog

(PARI) {m=0; q=5; s=3; t=2; forprime(p=6, 10^9, if((q-s==2) && (min(p-q, s-t)>m), m=min(p-q, s-t); print1(s, ", ") ); t=s; s=q; q=p; )}

Crossrefs

Subsequence of A001359.

Cf. A035789, A262935, A347280.

Sequence in context: A084748 A265784 A146243 * A214089 A108259 A093933

Adjacent sequences: A262933 A262934 A262935 * A262937 A262938 A262939

Keyword

nonn

Author

Dmitry Petukhov, Oct 04 2015

Status

approved