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 A105824 a(n) = sigma(n) mod 4. 11
 1, 3, 0, 3, 2, 0, 0, 3, 1, 2, 0, 0, 2, 0, 0, 3, 2, 3, 0, 2, 0, 0, 0, 0, 3, 2, 0, 0, 2, 0, 0, 3, 0, 2, 0, 3, 2, 0, 0, 2, 2, 0, 0, 0, 2, 0, 0, 0, 1, 1, 0, 2, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 3, 0, 0, 0, 2, 0, 0, 0, 3, 2, 2, 0, 0, 0, 0, 0, 2, 1, 2, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 2, 3, 0, 1, 2, 0, 0, 2, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Antti Karttunen, Table of n, a(n) for n = 1..16384 Index entries for sequences related to sums of divisors FORMULA a(n) = A010873(A000203(n)). - Antti Karttunen, Nov 07 2017 MAPLE A105824:= n-> (numtheory[sigma](n) mod 4): seq (A105824(n), n=1..105); # Jani Melik, Jan 26 2011 MATHEMATICA Table[Mod[DivisorSigma[1, n], 4], {n, 100}] (* Wesley Ivan Hurt, Nov 07 2017 *) PROG (PARI) a(n)=sigma(n)%4 CROSSREFS Cf. A000203, A010873, A248150, A072461, A072462, A191217. 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). Sequence in context: A298082 A085919 A352613 * A171911 A180193 A229964 Adjacent sequences: A105821 A105822 A105823 * A105825 A105826 A105827 KEYWORD easy,nonn AUTHOR Shyam Sunder Gupta, May 05 2005 STATUS approved

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Last modified September 19 16:10 EDT 2024. Contains 376013 sequences. (Running on oeis4.)