A033852 Integers k such that j(k)*phi(k) = sigma(k), where j(n) = A033831(n).

35, 105, 248, 418, 594, 744, 812, 1254

Offset: 1

Author

Naohiro Nomoto

Keywords

• more
• nonn

Comments

a(9) > 10^7. - Michel Marcus, Nov 05 2014

a(9) > 10^8. - Manfred Scheucher, May 30 2015

Crossrefs

Cf. A000010 (phi), A000203 (sigma), A033831.

Programs

PARI

isok(n) = sumdiv(n, d, (d>=3) && (q=n/d) && (q>=1) && (q<=d-2))*eulerphi(n) == sigma(n); \\ Michel Marcus, Nov 05 2014