A047272 Primes p such that p == 1 (mod 4) and Fibonacci((p-1)/4) is divisible by p.

61, 89, 109, 149, 269, 389, 401, 421, 521, 661, 701, 761, 769, 809, 821, 829, 1009, 1049, 1069, 1181, 1249, 1289, 1301, 1361, 1381, 1409, 1429, 1601, 1721, 1901, 1949, 2081, 2089, 2141, 2221, 2269, 2309, 2341, 2381, 2441, 2549, 2729, 2741, 2749, 2789

Offset

1,1

Comments

There are typos in Theorems 1 and 2 of Lehmer's paper. The condition a == 1 (mod 4) should be a == 1 (mod 2). - Eric Rowland, May 20 2018

Links

Table of n, a(n) for n=1..45.

E. Lehmer, On the quadratic character of the Fibonacci root, Fib. Quart., 4 (1966), 135-138.

E. Lehmer, On the quadratic character of the Fibonacci root (annotated scanned copy)

Mathematica

Select[Prime[Range[400]], Function[p, Mod[p, 4] == 1 && Divisible[Fibonacci[(p - 1)/4], p]]] (* Eric Rowland, May 20 2018 *)

Crossrefs

For nonprimes see A091982.

Sequence in context: A245759 A186457 A103812 * A123207 A309180 A038856

Adjacent sequences: A047269 A047270 A047271 * A047273 A047274 A047275

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

More terms from James A. Sellers, Jan 25 2000

New Name from Eric Rowland, May 20 2018

Status

approved