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A269239
Primes 10k + 7 preceding the maximal gaps in A269238.
3
7, 17, 67, 397, 997, 4657, 10687, 28097, 39397, 61057, 130987, 250307, 425417, 2385157, 2717567, 3207857, 5247257, 6996377, 7402237, 23363167, 27614507, 46359967, 103494037, 118884947, 499144627, 544698487, 705338497, 760949557, 1625986457
OFFSET
1,1
COMMENTS
Subsequence of A030432.
A269238 lists the corresponding record gap sizes. See more comments there.
LINKS
Alexei Kourbatov and Marek Wolf, Predicting maximal gaps in sets of primes, arXiv preprint arXiv:1901.03785 [math.NT], 2019.
EXAMPLE
The first two primes of the form 10k + 7 are 7 and 17, so a(1)=7. The next prime of this form is 37 and the gap 37-17=20 is a new record, so a(2)=17.
PROG
(PARI) re=0; s=7; forprime(p=17, 1e8, if(p%10!=7, next); g=p-s; if(g>re, re=g; print1(s", ")); s=p)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexei Kourbatov, Feb 20 2016
STATUS
approved