A270951 Numbers k such that k | A000129(k-1).

1, 7, 17, 23, 31, 41, 47, 71, 73, 79, 89, 97, 103, 113, 127, 137, 151, 167, 169, 191, 193, 199, 223, 233, 239, 241, 257, 263, 271, 281, 311, 313, 337, 353, 359, 367, 383, 385, 401, 409, 431, 433, 439, 449, 457, 463, 479, 487, 503, 521, 569, 577, 593, 599, 601, 607, 617, 631, 641, 647, 673, 719, 727, 743

Offset

1,2

Comments

Although A246692 and this sequence have similar names, note that this sequence generates prime numbers most of the time.

Composite terms of this sequence are A351337.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

7 is a term because A000129(6) = 70 is divisible by 7.

Mathematica

Select[Range[1000], Divisible[Fibonacci[#-1, 2], #]&] (* Jean-François Alcover, Jun 06 2017 *)

Prog

(PARI) a000129(n) = ([2, 1; 1, 0]^n)[2, 1];
for(n=1, 1e3, if(Mod(a000129(n-1), n) == 0, print1(n, ", ")));
(PARI) is(n)=(Mod([2, 1; 1, 0], n)^(n-1))[2, 1]==0 \\ Charles R Greathouse IV, Sep 11 2022

Crossrefs

Cf. A000129, A001132, A246692, A270834, A351337 (composite terms).

Sequence in context: A058529 A253408 A120681 * A001132 A308816 A254678

Adjacent sequences: A270948 A270949 A270950 * A270952 A270953 A270954

Keyword

nonn,easy

Author

Altug Alkan, Mar 26 2016

Status

approved