This site is supported by donations to The OEIS Foundation.



Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A201252 Initial primes in prime septuplets (p, p+2, p+8, p+12, p+14, p+18, p+20) preceding the maximal gaps in A201251. 3
5639, 88799, 284729, 1146779, 8573429, 24001709, 43534019, 87988709, 157131419, 522911099, 706620359, 1590008669, 2346221399, 3357195209, 11768282159, 30717348029, 33788417009, 62923039169, 68673910169, 88850237459, 163288980299, 196782371699, 421204876439 (list; graph; refs; listen; history; text; internal format)



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 more comments there. A233038 lists the corresponding primes at the end of the maximal gaps.


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

Tony Forbes, Prime k-tuplets

Alexei Kourbatov, Maximal gaps between prime k-tuples

Alexei Kourbatov, Tables of record gaps between prime constellations, arXiv preprint arXiv:1309.4053, 2013.

Eric W. Weisstein, k-Tuple Conjecture


The gap of 83160 between septuplets starting at p=5639 and p=88799 is the very first gap, so a(1)=5639. The gap of 195930 between septuplets starting at p=88799 and p=284729 is a maximal gap - larger than any preceding gap; therefore a(2)=88799. The next gap starts at p=284729 and is again a maximal gap, so a(3)=284729. The next gap is smaller, so it does not contribute to the sequence.


Cf. A022010 (prime septuplets p, p+2, p+8, p+12, p+14, p+18, p+20), A201251, A233038.

Sequence in context: A229591 A161193 A022010 * A247402 A184080 A234401

Adjacent sequences:  A201249 A201250 A201251 * A201253 A201254 A201255




Alexei Kourbatov, Nov 28 2011



Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 2 21:20 EST 2016. Contains 278694 sequences.