A339581 - OEIS

%I #24 Dec 25 2020 10:44:57

%S 1,2,89,1122659,19099919,85864769,26089808579,554688278429,

%T 4090932431513069,95405042230542329

%N Indices of records in A063377.

%C The records themselves begin 0,5,6,7,8,9,10,12,13,14.

%C a(11) <= 90616211958465842219 = A005602(15). Between a(10) and this upper bound could be another record which might not be listed in A005602.

%C a(n) == 9 mod 10 for n > 2 (see A063377). - _Michael S. Branicky_, Dec 24 2020

%D Carl Pomerance, Problem 81:21 (= 321), in R. K. Guy link.

%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) = A057331(n + 2) for n >= 2. - _David A. Corneth_, Dec 25 2020

%Y Cf. A005602, A057331, A063377, A063378, A339579, A339580.

%K nonn,more

%O 1,2

%A _N. J. A. Sloane_, Dec 24 2020

%E a(6) corrected and a(7) found by _David A. Corneth_, 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