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%I #9 Jan 09 2024 18:46:49
%S 8,104,592,8736,38912,473600,2466048,38054016,155493536,2015330304,
%T 10359014400,166290432000,636328345600,7645340651520,42424026529792,
%U 648494317126656,2599936977797120,32817383473149440,164708609085669376,3010983668199456768
%N Sum of the divisors of 8^n-1.
%H Max Alekseyev, <a href="/A366653/b366653.txt">Table of n, a(n) for n = 1..500</a>
%F a(n) = sigma(8^n-1) = A000203(A024088(n)).
%F a(n) = A075708(3*n). - _Max Alekseyev_, Jan 09 2024
%e a(5)=38912 because 8^5-1 has divisors {1, 7, 31, 151, 217, 1057, 4681, 32767}.
%p a:=n->numtheory[sigma](8^n-1):
%p seq(a(n), n=1..100);
%t DivisorSigma[1, 8^Range[30]-1]
%Y Cf. A024088, A000203, A057953, A059890, A366651, A366652, A366654.
%Y Cf. A075708, A366576, A366603, A366613, A366622, A366634, A366662, A102146, A366684, A366710.
%K nonn
%O 1,1
%A _Sean A. Irvine_, Oct 15 2023
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