A126703 Numbers k whose last k digits of k^k form a prime number.

143, 433, 1687, 3283, 14949

Offset

1,1

Comments

a(6) > 10^5. - Michael S. Branicky, Sep 28 2024

Links

Table of n, a(n) for n=1..5.

Mathematica

f[n_] := FromDigits[Take[IntegerDigits[n^n], -n]]; Do[If[PrimeQ[f[n]], Print[n]], {n, 8, 14949}] (* Ryan Propper, Apr 01 2007 *)

Prog

(Python)
from sympy import isprime
A126703_list = [n for n in range(1, 2000) if isprime(pow(n, n, 10**n))] # Chai Wah Wu, Mar 23 2018

Crossrefs

Indices of primes in A086756.

Sequence in context: A261074 A213337 A156963 * A111185 A074301 A156635

Adjacent sequences: A126700 A126701 A126702 * A126704 A126705 A126706

Keyword

base,hard,more,nonn

Author

Shyam Sunder Gupta, Feb 11 2007

Extensions

a(5) from Ryan Propper, Apr 01 2007

Status

approved