# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a366689 Showing 1-1 of 1 %I A366689 #7 Jan 04 2024 17:08:21 %S A366689 3,28,186,3458,21966,375816,2911272,45470096,340452396,6278429920, %T A366689 39543942612,706019328000,4708961513592,82162955169792, %U A366689 599236951715280,11195197038864384,68925937595777100,1179397832668228992,9136813499663186064,144079834776308121600 %N A366689 Sum of the divisors of 11^n+1. %H A366689 Max Alekseyev, Table of n, a(n) for n = 0..325 %F A366689 a(n) = sigma(11^n+1) = A000203(A034524(n)). %e A366689 a(4)=21966 because 11^4+1 has divisors {1, 2, 7321, 14642}. %p A366689 a:=n->numtheory[sigma](11^n+1): %p A366689 seq(a(n), n=0..100); %Y A366689 Cf. A034524, A000203, A366666, A366684, A366686, A366687, A366688, A366690, A366715. %K A366689 nonn %O A366689 0,1 %A A366689 _Sean A. Irvine_, Oct 16 2023 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE