OFFSET
1,2
COMMENTS
Numbers n such that A001923(n) == 1 (mod n).
a(11) > 10^7. - Hiroaki Yamanouchi, Aug 25 2015
MATHEMATICA
Union@Table[If[Mod[Sum[PowerMod[i, i, n], {i, 1, n}], n]==1, Print[n]; n], {n, 1, 20000}]
PROG
(PARI)
f(n)=lift(sum(k=1, n, Mod(k, n)^k));
for(n=1, 10^6, if(f(n)==1, print1(n, ", "))) /* Joerg Arndt, Apr 10 2011 */
(Python)
from itertools import accumulate, count, islice
def A188776_gen(): # generator of terms
yield 1
for i, j in enumerate(accumulate(k**k for k in count(2)), start=2):
if not j % i:
yield i
CROSSREFS
KEYWORD
nonn,more
AUTHOR
José María Grau Ribas, Apr 10 2011
EXTENSIONS
a(6)-a(9) from Lars Blomberg, May 10 2011
a(1) inserted and a(10) added by Hiroaki Yamanouchi, Aug 25 2015
STATUS
approved