A063795 - OEIS

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A063795

Numbers k such that usigma(k) = phi(k)*omega(k), where omega(k) is the number of distinct prime divisors of k.

35, 99, 357, 495, 1672, 2108, 3135, 3465, 3692, 5152, 11704, 14756, 15800, 18375, 20026, 23374, 23560, 25714, 25844, 33915, 35074, 39585, 49196, 55154, 56134, 66040, 86900, 99484, 104140, 105105, 110600, 116116, 124558, 141340, 157586

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..200

PROG

(PARI) us(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d));

for(n=1, 10^7, if(us(n)==eulerphi(n)*omega(n), print(n)))

(PARI) us(n) = sumdiv(n, d, if(gcd(d, n/d)==1, d))

{ n=0; for (m=1, 10^9, if(us(m)==eulerphi(m)*omega(m), write("b063795.txt", n++, " ", m); if (n==200, break)) ) } \\ Harry J. Smith, Aug 31 2009

CROSSREFS

Cf. A034448.