A071573 a(1) = 1; a(n) = a(n-1)-th nontotient number.

1, 14, 114, 594, 2532, 9658, 34066, 113930, 366358, 1141614, 3465398, 10291022, 29988178, 85961454, 242870564, 677436550, 1867877934

Offset: 1

Author

Robert G. Wilson v, Jun 20 2002

Keywords

• more
• nonn

Crossrefs

Cf. A005277, A072415.

Programs

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 = 1; Do[ Print[c]; c = 2b[[c]], {n, 0, 7}]

Formula

a(3)=114 is the 14th = a(2)-th term in A005277.

Extensions

Changed offset to match formula and a(11)-a(17) from Donovan Johnson, Feb 12 2011