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A215195 Numbers n such that A143615(n) = sigma(n) where sigma(n) = A000203(n). 0
1, 598, 1498, 54797260 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(5) (if it exists) > 10^8. - Hiroaki Yamanouchi, Sep 11 2014

LINKS

Table of n, a(n) for n=1..4.

PROG

(PARI) isok(n) = sum(m=1, n, if (gcd(n, m)==1, numdiv(m))) == sigma(n); \\ Michel Marcus, Nov 08 2014

CROSSREFS

Cf. A000203, A143615.

Sequence in context: A160149 A251224 A210384 * A262252 A252265 A029562

Adjacent sequences:  A215192 A215193 A215194 * A215196 A215197 A215198

KEYWORD

nonn,more

AUTHOR

Naohiro Nomoto, Aug 05 2012

EXTENSIONS

a(4) from Hiroaki Yamanouchi, Sep 11 2014

STATUS

approved

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Last modified May 21 10:41 EDT 2022. Contains 353908 sequences. (Running on oeis4.)