|
|
A115037
|
|
A number n is included if largest prime (or 1 if no prime divides) dividing the n-th Fibonacci number is itself a Fibonacci number.
|
|
0
|
|
|
1, 2, 3, 4, 5, 6, 7, 11, 12, 13, 17, 23, 29, 43, 46, 47, 58, 69, 83, 86, 129, 131, 137, 141, 166, 262, 274, 332, 359, 411, 431, 433, 449, 509, 569, 571, 718, 862, 866, 898, 1018, 1138, 1142, 1293, 1347, 1436
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
The 12th Fibonacci number is 144. The largest prime dividing 144 is 3 and 3 is the 4th Fibonacci number. So 12 is in the sequence.
|
|
PROG
|
(PARI) isfib(n) = my(k=n^2); k+=(k+1)<<2; issquare(k) || (n>0 && issquare(k-8));
isok(n) = my(f=fibonacci(n)); (f==1) || isfib(vecmax(factor(f)[, 1])); \\ Michel Marcus, Sep 06 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|