OFFSET
1,2
COMMENTS
Position of first occurrence of a gap of length P3 - P2 = 6*n - 2 containing no primes, bounded by twin primes (P1,P2) below and (P3,P4) above.
LINKS
Hugo Pfoertner, Table of n, a(n) for n = 1..63
EXAMPLE
a(4) = 1573, because the 4 primes P1 = 6*1573 - 1 = 9437, P2 = 6*1573 + 1 = 9439, P3 = P1 + 6*4 = 9461, P4 = 9463 produce the first occurrence of the gap P3 - P2 = 9461 - 9439 = 6*4 - 2 = 22. See also example in A329164.
PROG
(PARI) my(v=vector(31), p1=3, p2=5, p3=7, r=0, d); forprime(p4=11, 5e8, if(p2-p1==2&&p4-p3==2, d=(p3-p1)/6; if(v[d]==0, v[d]=(p1+p2)/12)); p1=p2; p2=p3; p3=p4); v
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Nov 09 2019
STATUS
approved