OFFSET
1,1
COMMENTS
Prime septuplets (p, p+2, p+8, p+12, p+14, p+18, p+20) are one of the two types of densest permissible constellations of 7 primes. Maximal gaps between septuplets of this type are listed in A201251; see comments and formulas there.
LINKS
Alexei Kourbatov, Table of n, a(n) for n = 1..52
Tony Forbes, Prime k-tuplets
Alexei Kourbatov, Maximal gaps between prime septuplets
Alexei Kourbatov, Tables of record gaps between prime constellations, arXiv preprint arXiv:1309.4053, 2013.
Eric W. Weisstein, k-Tuple Conjecture
EXAMPLE
The gap of 83160 between septuplets starting at p=5639 and p=88799 is the very first gap, so a(1)=88799. The gap of 195930 between septuplets starting at p=88799 and p=284729 is a maximal (record) gap - larger than any preceding gap; therefore a(2)=284729. The next gap of 341880 ending at 626609 is again a record, so a(3)=626609. The next gap is smaller, so that gap does not contribute a new term to the sequence.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexei Kourbatov, Dec 08 2013
EXTENSIONS
Terms a(11) and beyond from b-file by Andrew Howroyd, Feb 05 2018
STATUS
approved