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

Author

Altug Alkan, Mar 26 2016

Keywords

• nonn
• easy

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.

Examples

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

Links

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

Crossrefs

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

Programs

Mathematica

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

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