A062558 Number of nonisomorphic cyclic subgroups of dihedral group with 2n elements.

2, 2, 3, 3, 3, 4, 3, 4, 4, 4, 3, 6, 3, 4, 5, 5, 3, 6, 3, 6, 5, 4, 3, 8, 4, 4, 5, 6, 3, 8, 3, 6, 5, 4, 5, 9, 3, 4, 5, 8, 3, 8, 3, 6, 7, 4, 3, 10, 4, 6, 5, 6, 3, 8, 5, 8, 5, 4, 3, 12, 3, 4, 7, 7, 5, 8, 3, 6, 5, 8, 3, 12, 3, 4, 7, 6, 5, 8, 3, 10, 6, 4, 3, 12, 5, 4, 5, 8, 3, 12, 5, 6, 5, 4, 5, 12, 3, 6, 7, 9, 3

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..1001

Formula

a(n) = A000005(n) + A000035(n) = tau(n)+(n mod 2), where tau(n) = the number of divisors of n.

Prog

(PARI) a(n) = numdiv(n) + (n % 2) \\ Michel Marcus, Jun 17 2013

Crossrefs

Cf. A000005, A000045, A023645, A062249 (labeled case).

One more than A076984.

Sequence in context: A073734 A231335 A271237 * A072789 A126302 A200648

Adjacent sequences: A062555 A062556 A062557 * A062559 A062560 A062561

Keyword

nonn

Author

Vladeta Jovovic, Jul 03 2001

Status

approved