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A140198 A002326((k-1)/2) for composite numbers k from A141229. 0
18, 100, 1210, 2028, 6498, 23548, 49284, 146068, 201898, 223260, 296274, 564898, 1020100, 1213594, 2230930, 2666298, 3285748, 4304178, 5147788, 5703298, 5896980, 7606564, 9349410, 11645554, 19392748, 25067908, 31754524, 41661514, 42386748, 51755988, 54296298 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..31.

MATHEMATICA

r[n_] := EulerPhi[n]/MultiplicativeOrder[2, n]; d[n_] := DivisorSum[n, r[#] &]; f[n_] := (m = MultiplicativeOrder[2, n])*d[n] - m + 1; MultiplicativeOrder[2, #] & /@  Select[Range[10^5], CompositeQ[#] && Total@(r /@ Divisors[#]) - 1 == 3 &] (* Amiram Eldar, Sep 12 2019 *)

CROSSREFS

Cf. A002326, A141229, A001122, A006694.

Sequence in context: A064604 A301542 A231138 * A107600 A229326 A008528

Adjacent sequences:  A140195 A140196 A140197 * A140199 A140200 A140201

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Jun 15 2008

EXTENSIONS

a(4) corrected and more terms added by Amiram Eldar, Sep 12 2019

STATUS

approved

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Last modified January 23 03:15 EST 2022. Contains 350504 sequences. (Running on oeis4.)