A197219 a(0) = 2, a(n) = Lucas(phi(n)) for n > 0.

2, 1, 1, 3, 3, 7, 3, 18, 7, 18, 7, 123, 7, 322, 18, 47, 47, 2207, 18, 5778, 47, 322, 123, 39603, 47, 15127, 322, 5778, 322, 710647, 47, 1860498, 2207, 15127, 2207, 103682, 322, 33385282, 5778, 103682, 2207, 228826127, 322, 599074578, 15127, 103682, 39603

Offset: 0

Author

T. D. Noe, Oct 12 2011

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A000010, A000032, A065449, A065451, A197218 (phi(Lucas(n))).

Programs

Magma

[2] cat [Lucas(EulerPhi(n)): n in [1..60]]; // Vincenzo Librandi, Oct 13 2011

Mathematica

Table[LucasL[EulerPhi[n]], {n, 0, 50}]

PARI

a(n) = if(n==0, 2, fibonacci(eulerphi(n)+1) + fibonacci(eulerphi(n)-1)) \\ G. C. Greubel, Dec 22 2017

Formula

a(n) = A000032(A000010(n)) for n > 0.