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%I #26 Jan 18 2022 05:42:59
%S 1,3,4,7,8,9,13,14,16,17,18,19,21,23,24,26,27,28,30,31,32,34,36,37,38,
%T 39,42,43,44,46,47,48,49,51,52,53,54,56,57,59,61,62,63,64,67,68,69,70,
%U 71,72,73,74,76,78,79,81,83,84,86,87,88,90,91,92,93,94,96
%N Numbers k that divide the sum of divisors of Fibonacci(k).
%C This sequence is infinite (Luca, 2002).
%H Amiram Eldar, <a href="/A350690/b350690.txt">Table of n, a(n) for n = 1..1197</a>
%H Florian Luca, <a href="https://www.fq.math.ca/Scanned/40-5/advanced40-5.pdf">Problem H-590</a>, Advanced Problems and Solutions, The Fibonacci Quarterly, Vol. 40, No. 5 (2002), p. 472; <a href="https://www.fq.math.ca/Scanned/41-4/advanced41-4.pdf">Arithmetic Functions of Fibonacci Numbers</a>, Solution to Problem H-590 by J.-Ch. Schlage-Puchta and J. Spilker, ibid., Vol. 41, No. 4 (2002), pp. 382-384.
%e 3 is a term since 3 divides sigma(Fibonacci(3)) = sigma(2) = 3.
%e 4 is a term since 4 divides sigma(Fibonacci(4)) = sigma(3) = 4.
%t Select[Range[100], Divisible[DivisorSigma[1, Fibonacci[#]], #] &]
%o (Python) from sympy import divisor_sigma, fibonacci
%o print([k for k in range(1, 97) if divisor_sigma(fibonacci(k)) % k == 0])
%o # _Karl-Heinz Hofmann_, Jan 12 2022
%Y Cf. A000045, A000203, A063477.
%Y Similar sequences: A074698, A075775.
%K nonn
%O 1,2
%A _Amiram Eldar_, Jan 12 2022
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