A215195 Numbers n such that A143615(n) = sigma(n) where sigma(n) = A000203(n).

1, 598, 1498, 54797260

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