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A214153 Numbers k for which k and tau(k) are both congruent to 1 modulo 3. 1

%I #18 Aug 29 2020 06:53:36

%S 1,10,22,34,46,55,58,64,82,85,91,94,106,112,115,118,133,142,145,166,

%T 178,187,202,205,208,214,217,226,235,247,253,259,262,265,274,280,295,

%U 298,301,304,319,334,343,346,355,358,382,391,394,403,415,427,445,451

%N Numbers k for which k and tau(k) are both congruent to 1 modulo 3.

%H Amiram Eldar, <a href="/A214153/b214153.txt">Table of n, a(n) for n = 1..10000</a>

%e The divisors of 10 are: 1, 2, 5, 10 (4 divisors). 10 and 4 are both congruent to 1 modulo 3. Thus 10 is a member of this sequence.

%t Select[Range[1, 500, 3], Mod[DivisorSigma[0, #], 3] == 1 &] (* _T. D. Noe_, Jul 09 2012 *)

%Y Intersection of A016777 and A211337.

%Y Cf. A000005.

%K nonn

%O 1,2

%A _Gerasimov Sergey_, Jul 05 2012

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Last modified March 28 12:26 EDT 2024. Contains 371254 sequences. (Running on oeis4.)