OFFSET
0,3
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..1000
EXAMPLE
a(18) = 8 because L(18) = 5778 = 2 * 3^3 * 107 whose odd divisors are 8 in number: {1, 3, 9, 27, 107, 321, 963, 2889}. a(n) = 2 iff n is in A001606 (Indices of prime Lucas numbers).
MATHEMATICA
Table[luc = LucasL[n]; r = IntegerExponent[luc, 2]; DivisorSigma[0, luc/2^r], {n, 0, 100}] (* T. D. Noe, Jul 29 2011 *)
Table[Count[Divisors[LucasL[n]], _?OddQ], {n, 0, 80}] (* Harvey P. Dale, Mar 28 2019 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post, Jul 28 2011
STATUS
approved