OFFSET
1,1
FORMULA
a(5) = 373 = 746/2, where 746 is the a(4) = 149th term in A005277.
MATHEMATICA
a = Table[0, {10^6}]; Do[b = EulerPhi[n]/2; If[b < 10^6 + 1, a[[b]] = 1], {n, 1, 2 10^7}]; b = Select[ Range[10^6], a[[ # ]] == 0 &]; c = 2; Do[ Print[c]; c = b[[c]], {n, 0, 17}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jun 17 2002
EXTENSIONS
Edited by Robert G. Wilson v, Jun 20 2002
a(18)-a(31) from Donovan Johnson, Oct 29 2010
STATUS
approved