A162908 Pairs of central divisors of A089229(n).

2, 3, 2, 4, 2, 5, 3, 4, 2, 7, 3, 5, 3, 6, 4, 5, 3, 7, 2, 11, 4, 6, 2, 13, 3, 9, 4, 7, 5, 6, 4, 8, 3, 11, 2, 17, 5, 7, 2, 19, 3, 13, 5, 8, 6, 7, 4, 11, 5, 9, 2, 23, 6, 8, 5, 10, 3, 17, 4, 13, 6, 9, 5, 11, 7, 8, 3, 19, 2, 29, 6, 10, 2, 31, 7, 9, 5, 13, 6, 11, 4, 17, 3, 23, 7, 10, 8, 9, 2, 37, 5, 15, 4, 19

Offset

1,1

Comments

The central divisors are the two complementary divisors closest to the square

root of a number, as tabulated in A162348.

Links

Table of n, a(n) for n=1..94.

Formula

a(2n-1)= A033676(A089229(n)). a(2n)=A033677(A089229(n)). - R. J. Mathar, Jul 19 2009

Example

a(1)=2 and a(2)=3 since A089229(1)=6 with divisors 1, 2, 3, 4.
a(3)=2 and a(4)=4 since A089229(2)=8 with divisors 1, 2, 4, 8.
a(5)=2 and a(6)=5 since A089229(3)=10 with divisors 1, 2, 5, 10.

Crossrefs

Cf. A089229, A162361.

Sequence in context: A319702 A365791 A331252 * A373558 A222817 A344324

Adjacent sequences: A162905 A162906 A162907 * A162909 A162910 A162911

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Jul 17 2009

Extensions

Missing pairs inserted by R. J. Mathar, Jul 19 2009

Status

approved