login
A067878
Numbers n such that sigma(n)=phi(n*omega(n)-1).
0
1, 10, 33, 46, 65, 77, 123, 136, 221, 371, 385, 423, 513, 532, 545, 572, 660, 702, 753, 1248, 1566, 1643, 1720, 2033, 2635, 3243, 4533, 4798, 5177, 5346, 5495, 5605, 6460, 7463, 7565, 7683, 7739, 8201, 9342, 9741, 10780, 10792, 11679, 11880, 12256
OFFSET
1,2
COMMENTS
Omega(n) refers to unique prime factors of n, i.e., prime factors taken without multiplicity. - Harvey P. Dale, Feb 02 2015
MATHEMATICA
Select[Range[13000], DivisorSigma[1, #]==EulerPhi[#*PrimeNu[#]-1]&] (* Harvey P. Dale, Feb 02 2015 *)
CROSSREFS
Sequence in context: A137723 A256352 A255533 * A067877 A367031 A348427
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Mar 02 2002
STATUS
approved