OFFSET
1,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..20000
FORMULA
G.f.: Sum_{k>=2} F(k)*x^F(k)/(1 - x^F(k)), where F(k) is the k-th Fibonacci number (A000045). - Ilya Gutkovskiy, Jan 06 2017
MAPLE
a:= n-> add(`if`(issqr(5*d^2+4) or issqr(5*d^2-4), d, 0)
, d=numtheory[divisors](n)):
seq(a(n), n=1..100); # Alois P. Heinz, Jan 07 2017
MATHEMATICA
nmax = 100; With[{fibs = Fibonacci[Range[2, Floor[Log[nmax*Sqrt[5]] / Log[GoldenRatio]] + 1]]}, Table[Total[Select[fibs, Divisible[n, #1] & ]], {n, 1, nmax}]] (* Vaclav Kotesovec, Apr 29 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved