OFFSET
1,1
LINKS
FORMULA
a(n) = 2*n for n >= 3.
Proof: By Lagrange's theorem in group theory we have that n divides a(n) for all n. A group of order n and with an element of order n is the cyclic group of order n, hence being abelian. On the other hand, the dihedral group D_{2n} is non-abelian for n >= 3 and contains an element of order n. - Jianing Song, Aug 11 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Yue Yu, Apr 01 2023
STATUS
approved