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A326141 Odd numbers n for which A318879(n) is not zero and A318879(n) divides A318878(n); odd numbers such that A326140(n) = A318879(n). 5
105, 195, 4785, 22515, 56865, 228285, 237315, 484245, 671853, 1838145, 1946955, 3446895, 4522695, 12955245, 37730865, 52475055, 53568885, 87612975 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Not a subsequence of A036798, even though many terms are members.

Questions: Are all terms multiples of three? Multiples of 3^(2k+1) but not of 3^(2k)? Are any of the terms included in A228058, A326137?

LINKS

Table of n, a(n) for n=1..18.

Index entries for sequences where any odd perfect numbers must occur

PROG

(PARI) isA326141(n) = if(!(n%2), 0, my(t=0, u=0); fordiv(n, d, d -= 2*eulerphi(d); if(d<0, t -= d, u += d)); (gcd(t, u)==u));

CROSSREFS

Cf. A033879, A083254, A036798, A228058, A318878, A318879, A326137, A326140.

Cf. also A325981, A326131.

Sequence in context: A046887 A026066 A167629 * A044337 A044718 A239827

Adjacent sequences:  A326138 A326139 A326140 * A326142 A326143 A326144

KEYWORD

nonn,more

AUTHOR

Antti Karttunen, Jun 09 2019

STATUS

approved

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Last modified February 18 04:48 EST 2020. Contains 332011 sequences. (Running on oeis4.)