A217738 - OEIS

%I #17 Mar 24 2021 09:52:30

%S 60,108,180,240,540,600,660,768,1008,1200,1320,1620,1800,1860,2160,

%T 2520,2688,2736,3000,3060,3300,3360,3528,3888,4200,4800,4860,4968,

%U 5280,5520,5580,5880,6120,6480,6600,6720,6840,7320,7560,7680,8100,8208,8640,9000,9180,9240,9600

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

%C Indices of 0's in A217737.

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

%H Alois P. Heinz, <a href="/A217738/b217738.txt">Table of n, a(n) for n = 1..1000</a> (first 370 terms from Harvey P. Dale)

%t Select[Range[10000],Divisible[Fibonacci[#],#(#+1)]&] (* _Harvey P. Dale_, Aug 14 2014 *)

%o (Python)

%o prpr, prev = 0, 1

%o for i in range(1, 1000):

%o     cur = prpr + prev

%o     a = prev % (i*(i+1))

%o     if a==0:

%o       print(str(i), end=', ')

%o     prpr, prev = prev, cur

%Y Cf. A000045, A002378, A217737.

%K nonn

%O 1,1

%A _Alex Ratushnyak_, Mar 22 2013