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A195465 The first a(n) n-gap primes are lessers of twin primes, a(n) maximal. 1
0, 5, 5, 17, 5, 6, 14, 6, 24, 75, 2, 4, 27, 11, 48, 50, 46, 9, 21, 7, 16, 137, 4, 55, 85, 14, 111, 24, 102, 291, 67, 89, 155, 180, 137, 330, 127, 413, 250, 241, 332, 619, 139, 234, 453, 929, 94, 160, 169, 22, 131, 434 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For definition of n-gap primes, see comment to A195270.

Conjecture: a(n)>0 for n>1. This conjecture is equivalent to the conjecture that all terms of A195325 are lessers of twin primes.

LINKS

Table of n, a(n) for n=1..52.

MAPLE

a:= proc(n) local i, p, q;

      p, q:= 2, 3;

      for i from 0 do

        while nextprime(n*p) < (n*q) do

          p, q:= q, nextprime(q)

        od;

        if not isprime(p+2) then return i fi;

        p, q:= q, nextprime(q)

      od

    end:

seq(a(n), n=1..20);  # Alois P. Heinz, Sep 20 2011

CROSSREFS

Cf. A195325, A080192, A195270, A195271, A164368, A194658, A164294.

Sequence in context: A189316 A154232 A194615 * A173464 A072272 A273502

Adjacent sequences:  A195462 A195463 A195464 * A195466 A195467 A195468

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Sep 19 2011

STATUS

approved

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Last modified July 13 13:48 EDT 2020. Contains 335688 sequences. (Running on oeis4.)