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A262359 Numbers n such that denominator(sigma(n)/n) = 6. 0
18, 22932, 14520576, 1610563584, 1907020800, 2836487808, 6399679104, 70912195200, 82819376640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

sigma(18)/18 = 13/6, hence 18 is a term.

PROG

(PARI) isok(n) = denominator(sigma(n, -1)) == 6;

(PARI) lista(nn) = {k = 6; nb = 0; while (nb != nn, if (denominator(sigma(k, -1)) == 6, print1(k, ", "); nb++); k += 6; ); }

CROSSREFS

Cf. similar sequences with A017666(n)=k: A159907 (k=2), A245775 (k=3), A229088 (k=4), A067237 (k=5).

Sequence in context: A201986 A153301 A129042 * A202155 A296653 A255406

Adjacent sequences:  A262356 A262357 A262358 * A262360 A262361 A262362

KEYWORD

nonn,more

AUTHOR

Michel Marcus, Sep 19 2015

STATUS

approved

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Last modified November 30 05:00 EST 2021. Contains 349418 sequences. (Running on oeis4.)