OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1408 (terms 1..1000 from T. D. Noe, using Blair Kelly's data)
Blair Kelly, Fibonacci and Lucas Factorizations
EXAMPLE
a(8) = 10 because Fibonacci(8) = 21 and the sum of the prime divisors {3, 7} equals 10.
MAPLE
with (numtheory):with(combinat, fibonacci):
sopf:= proc(n) local e, j; e := ifactors(fibonacci(n))[2]:
add (e[j][1], j=1..nops(e)) end:
seq (sopf(n), n=1..100); # Michel Lagneau, Nov 13 2012
A080648 := proc(n)
A008472(combinat[fibonacci](n)) ;
end proc: # R. J. Mathar, Nov 15 2012
# third Maple program:
a:= n-> add(i[1], i=ifactors((<<0|1>, <1|1>>^n)[1, 2])[2]):
seq(a(n), n=1..48); # Alois P. Heinz, Sep 03 2019
MATHEMATICA
Table[Apply[Plus, Transpose[FactorInteger[Fibonacci[n]]][[1]]], {n, 3, 100}] (* Pe *)
Array[Plus@@First/@FactorInteger[Fibonacci[ # ]]&, 40 ] (* Michel Lagneau, Nov 13 2012 *)
PROG
(PARI) a(n) = vecsum(factor(fibonacci(n))[, 1]); \\ Michel Marcus, Oct 15 2019
(Magma) [&+PrimeDivisors(Fibonacci(n)):n in [1..48]]; // Marius A. Burtea, Oct 15 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Feb 28 2003
STATUS
approved