OFFSET
1,2
COMMENTS
p and p+2n are primes and there is one prime in the range p+1 to p+2n-1.
a(n) is the prime for which 2n+2 first occurs in A031131.
LINKS
Martin Raab, Table of n, a(n) for n = 1..469 (terms 1..342 from Robert G. Wilson v)
Mersenne Forum, Gaps between non-consecutive primes
MATHEMATICA
nn=51; t=Table[0, {nn}]; t[[1]]=-1; cnt=1; n=1; While[cnt<nn, n++; d=(Prime[n+2]-Prime[n])/2; If[d<=nn && t[[d]]==0, cnt++; t[[d]]=Prime[n]]]; t=Rest[t]
Flatten[Table[Select[Partition[Prime[Range[20000]], 3, 1], #[[3]]-#[[1]] == 2n+2&, 1], {n, 41}], 1][[All, 1]] (* Harvey P. Dale, Jun 26 2017 *)
CROSSREFS
KEYWORD
sign
AUTHOR
T. D. Noe, Sep 11 2008
EXTENSIONS
Definition edited by N. J. A. Sloane, Nov 07 2020
STATUS
approved