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%I #34 Dec 25 2020 10:41:42
%S 1,3,90,1122660,19099920,85864770,26089808580,554688278430,
%T 4090932431513070,95405042230542330
%N Indices of records in A339579.
%C The records themselves begin 4,5,6,7,8,9,10,12,13,14.
%C a(11) <= 90616211958465842220.
%D Carl Pomerance, Problem 81:21 (= 321), in R. K. Guy problem list.
%H R. K. Guy, editor, <a href="/A339579/a339579.pdf">Western Number Theory Problems, 1985-12-21 & 23</a>, Typescript, Jul 13 1986, Dept. of Math. and Stat., Univ. Calgary, 11 pages. Annotated scan of pages 1, 3, 7, 9, with permission.
%F a(n) = A339581(n) + 1 for n >= 2. - _David A. Corneth_, Dec 24 2020
%e 90 is in the sequence as A339579(90) = 6 (90*2^k - 1 is prime for k = 0..5 and composite for k = 6) and A339579(m) < 6 for m < 90. - _David A. Corneth_, Dec 24 2020
%Y Cf. A063377, A124514, A125113, A339579, A339581.
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_, Dec 24 2020
%E a(8)-a(10) were taken from A057331 and the bound on a(11) was taken from A005602. - _David A. Corneth_ and _Amiram Eldar_, Dec 25 2020
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