A217738 Numbers k such that Fibonacci(k) is divisible by k*(k+1).

60, 108, 180, 240, 540, 600, 660, 768, 1008, 1200, 1320, 1620, 1800, 1860, 2160, 2520, 2688, 2736, 3000, 3060, 3300, 3360, 3528, 3888, 4200, 4800, 4860, 4968, 5280, 5520, 5580, 5880, 6120, 6480, 6600, 6720, 6840, 7320, 7560, 7680, 8100, 8208, 8640, 9000, 9180, 9240, 9600

Offset

1,1

Comments

Indices of 0's in A217737.

Conjectures: the sequence is infinite; all terms are divisible by 12.

Links

Alois P. Heinz, Table of n, a(n) for n = 1..1000 (first 370 terms from Harvey P. Dale)

Mathematica

Select[Range[10000], Divisible[Fibonacci[#], #(#+1)]&] (* Harvey P. Dale, Aug 14 2014 *)

Prog

(Python)
prpr, prev = 0, 1
for i in range(1, 1000):
    cur = prpr + prev
    a = prev % (i*(i+1))
    if a==0:
      print(str(i), end=', ')
    prpr, prev = prev, cur

Crossrefs

Cf. A000045, A002378, A217737.

Sequence in context: A044001 A258700 A008887 * A351548 A182683 A174601

Adjacent sequences: A217735 A217736 A217737 * A217739 A217740 A217741

Keyword

nonn

Author

Alex Ratushnyak, Mar 22 2013

Status

approved