A040070 -id:A040070 - cp's OEIS frontend

A040069 Primes p such that x^3 = 15 has a solution mod p.

2, 3, 5, 7, 11, 17, 23, 29, 31, 41, 47, 53, 59, 67, 71, 79, 83, 89, 101, 107, 113, 131, 137, 149, 167, 173, 179, 191, 197, 223, 227, 229, 233, 239, 251, 257, 263, 269, 277, 281, 283, 293, 311, 317, 331, 347, 353

Offset: 1

N. J. A. Sloane

Complement of A040070 relative to A000040. - Vincenzo Librandi, Sep 13 2012

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A000040, A040070.

[p: p in PrimesUpTo(450) | exists(t){x : x in ResidueClassRing(p) | x^3 eq 15}]; // Vincenzo Librandi, Sep 11 2012

ok [p_]:=Reduce[Mod[x^3 - 15, p] == 0, x, Integers] =!= False;  Select[Prime[Range[180]], ok] (* Vincenzo Librandi, Sep 11 2012 *)

select(n->ispower(Mod(15, n),3), primes(500)) \\ Charles R Greathouse IV, Sep 11 2012

A058953 Numbers k of the form k=p*2^x, with p prime and x>=0, such that tau(k)-m = A058933(k) where tau(k) is the number of divisors of k and m is 0 or 1.

Original entry on oeis.org

2, 3, 10, 28, 176, 832, 4352, 19456, 47104, 1900544, 4063232, 77594624, 687865856, 2885681152

Offset: 1

Naohiro Nomoto, Jan 13 2001

(p=2 => m=1); ( Conjecture: [for p>2]; if p=A040069 then m=0 else m=1. )

Cf. A000005, A040069, A040070, A058933.

Offset corrected, title clarified, and a(12)-a(13) from Sean A. Irvine, Sep 07 2022

cp's OEIS Frontend

A040069 Primes p such that x^3 = 15 has a solution mod p.

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