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A120839
a(n) is the n-th positive integer which is coprime to the n-th Fibonacci number.
2
1, 2, 5, 5, 6, 11, 7, 13, 19, 13, 11, 35, 13, 15, 37, 26, 17, 39, 19, 43, 45, 22, 23, 85, 31, 26, 59, 46, 29, 87, 31, 58, 65, 34, 47, 125, 37, 39, 77, 101, 41, 95, 43, 67, 121, 46, 47, 179, 53, 68, 101, 77, 53, 125, 68, 109, 119, 58, 59, 263, 61, 62, 145, 115, 81, 133, 67
OFFSET
1,2
LINKS
EXAMPLE
55 is the 10th Fibonacci number. 1,2,3,4,6,7,8,9,12,13,14,16,... is the sequence of positive integers which are coprime to 55. 13 is the 10th of these integers, so a(10)=13.
MATHEMATICA
Table[Block[{m = Fibonacci@ n, r = {1}, k = 2}, While[Length@ r < n, If[GCD[k, m] == 1, AppendTo[r, k], Nothing]; k++]; Last@ r], {n, 67}] // Flatten (* Michael De Vlieger, Dec 26 2019 *)
CROSSREFS
Diagonal of A129322.
Sequence in context: A145434 A220426 A117899 * A332525 A196608 A129228
KEYWORD
nonn
AUTHOR
Leroy Quet, Aug 18 2006
EXTENSIONS
Extended by Ray Chandler, Aug 22 2006
STATUS
approved