A227199 Primes that divide some term of A006720.

2, 3, 7, 11, 23, 41, 47, 53, 59, 61, 71, 73, 83, 97, 101, 113, 127, 139, 149, 157, 173, 179, 181, 191, 197, 199, 211, 223, 229, 239, 257, 263, 271, 277, 281, 307, 331, 337, 347, 359, 373, 379, 383, 389, 397, 409, 419, 433, 439, 443, 463, 467, 479, 499, 509

Offset: 1

Author

Jeremy Rouse, Sep 18 2013

Keywords

• easy
• nonn

Comments

The density of primes in this sequence is 11/21.

If p divides A006720(n) for some n, then the smallest such n is <= (1/2)*((sqrt(p)+1)^2+3).

Examples

			11 is in the sequence because 11 divides A006720(10) = 1529.
		

Links

• Jeremy Rouse, Table of n, a(n) for n = 1..10000
• R. Jones and J. Rouse, Galois Theory of Iterated Endomorphisms, Proceedings of the London Mathematical Society, 100, no. 3 (2010), 763-794.

Programs

Magma

[ n : n in [2..500] | IsPrime(n) and (n ne 37) and (Order(EllipticCurve([GF(n)!0,0,1,-1,0])![0,0,1]) mod 2 eq 1) ];