|
%I #13 May 13 2013 01:54:20
%S 0,0,2,0,0,14,0,0,36,0,0,390,0,0,744,0,0,5040,0,0,11816,0,0,154752,0,
%T 0,213840,0,0,1999872,0,0,3564360,0,0,46656000,0,0,63517896,0,0,
%U 526048320,0,0,1465647264,0,0,16665772032,0,0,20377766312,0,0,173039328000
%N Sum of even divisors of Fibonacci(n).
%H Charles R Greathouse IV, <a href="/A193294/b193294.txt">Table of n, a(n) for n = 1..1000</a>
%e a(6) = 14 because Fibonacci(6) = 8, and the sum of the even divisors {2, 4, 8} = 14.
%t Table[Total[Select[Divisors[Fibonacci[n]], EvenQ[ # ]&]], {n, 75}]
%o (PARI) a(n)=if(n%3,0,2*sigma(fibonacci(n)/2)) \\ _Charles R Greathouse IV_, Jul 31 2011
%Y Cf. A000045, A193291.
%K nonn
%O 1,3
%A _Michel Lagneau_, Jul 21 2011
|
