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%I #12 Jul 30 2021 19:12:31
%S 1,3,4,0,6,5,1,1,6,4,5,0,0,3,3,3,4,4,6,0,4,1,3,4,3,0,5,0,2,2,4,0,6,5,
%T 6,0,3,4,0,6,0,5,2,0,1,2,6,5,1,2,2,0,5,1,2,1,3,6,4,0,6,5,6,1,0,4,5,0,
%U 5,4,2,6,4,2,5,0,5,0,3,4,2,0,0,0,3,6,1,5,6,3,0,0,2,4,1,0,0,3,2,0,4,6,6,0,3
%N a(n) = sigma(n) (mod 7).
%H Antti Karttunen, <a href="/A105826/b105826.txt">Table of n, a(n) for n = 1..16384</a>
%H <a href="/index/Su#sums_of_divisors">Index entries for sequences related to sums of divisors</a>
%p A105826:= n-> (numtheory[sigma](n) mod 7):
%p seq (A105826(n), n=1..105); # _Jani Melik_, Jan 26 2011
%t Mod[DivisorSigma[1,Range[110]],7] (* _Harvey P. Dale_, Jul 30 2021 *)
%o (PARI) a(n)=sigma(n)%7
%Y Cf. A000203.
%Y Sequences sigma(n) mod k: A053866 (k=2), A074941 (k=3), A105824 (k=4), A105825 (k=5), A084301 (k=6), A105826 (k=7), A105827 (k=8).
%K easy,nonn
%O 1,2
%A _Shyam Sunder Gupta_, May 05 2005
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