|
| |
|
|
A132125
|
|
Number of distinct Fibonacci divisors of the factorial of n.
|
|
0
| |
|
|
1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 8, 8, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
FORMULA
| a(n)=A005086(A000142(n)).
|
|
|
EXAMPLE
| a(8)=7 because 8!=40320=2^7*3^2*5*7 has the seven divisors 1, 2, 3, 5, 8, 21
and 144 which are also Fibonacci numbers.
|
|
|
MAPLE
| A005086 := proc(n) local a, i, f; a := 0 ; for i from 2 do f := combinat[fibonacci](i) ; if f > n then RETURN(a) ; fi ; if n mod f = 0 then a := a+1 ; fi ; od: end: A000142 := proc(n) n! ; end: A := proc(n) A005086(A000142(n)) ; end: seq(A(n), n=1..80);
|
|
|
CROSSREFS
| Cf. A005086, A000142, A000045.
Sequence in context: A141258 A117656 A101918 * A102672 A114955 A060207
Adjacent sequences: A132122 A132123 A132124 * A132126 A132127 A132128
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 31 2007
|
| |
|
|
