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%I #13 Oct 11 2021 16:53:44
%S 0,1,1,1,1,8,1,5,1,10,1,18,1,12,20,5,1,23,1,26,17,16,1,58,1,18,10,42,
%T 1,70,1,21,32,22,40,39,1,24,23,90,1,106,1,54,71,28,1,98,1,55,44,34,1,
%U 104,37,106,29,34,1,240,1,36,77,21,65,160,1,38,56,200,1,175,1,42,60,78,94,154,1,146
%N a(n) = Sum_{d|n} (d^2 mod n).
%H Robert Israel, <a href="/A338935/b338935.txt">Table of n, a(n) for n = 1..10000</a>
%e a(6) = (1^2 mod 6) + (2^2 mod 6) + (3^2 mod 6) + (6^2 mod 6) = 1+4+3+0 = 8.
%p f:= n -> add(t^2 mod n, t = numtheory:-divisors(n)):
%p map(f, [$1..100]);
%t Table[Total[Mod[Divisors[n]^2,n]],{n,80}] (* _Harvey P. Dale_, Oct 11 2021 *)
%o (PARI) a(n) = sumdiv(n, d, lift(Mod(d, n)^2)); \\ _Michel Marcus_, Nov 16 2020
%Y Cf. A000430 (a(n)=1), A338930 (a(n) is prime).
%K nonn
%O 1,6
%A _J. M. Bergot_ and _Robert Israel_, Nov 16 2020
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