1,2

a(n) = phi(n)*phi(2*n). - Vladeta Jovovic (vladeta(AT)Eunet.yu), May 02 2005

Cf. A000252, A070732.

Cf. A000010.

Adjacent sequences: A082950 A082951 A082952 this_sequence A082954 A082955 A082956

Sequence in context: A070336 A053026 A119318 this_sequence A009289 A070335 A020954

mult,nonn

Yuval Dekel (dekelyuval(AT)hotmail.com), May 26 2003