A279667 Number of subparts (also number of odd divisors) of the smallest number k such that the symmetric representation of sigma(k) has n layers.

1, 2, 4, 4, 6, 8, 8, 12, 12, 12, 16, 24, 24, 18, 32, 32, 24, 36, 24, 36, 32, 48, 36, 32, 48, 48, 48

Offset: 1

Author

Omar E. Pol, Dec 16 2016

Keywords

• nonn
• more

Comments

In other words: number of subparts (also number of odd divisors) of the smallest number k such that the symmetric representation of sigma(k) has at least a part of width n.

Note that the number of subparts in the symmetric representation of sigma(n) equals A001227(n), the number of odd divisors of n.

For more information about the subparts and the layers see A279387.

Examples

			For n = 5 we have that 360 is the smallest number k whose symmetric representation of sigma(k) has parts of width 5. The structure has six subparts: [719, 237, 139, 71, 2, 2]. On the other hand, 360 has six odd divisors: {1, 3, 5, 9, 15, 45}, so a(5) = 6.
		

Crossrefs

Cf. A000203, A001227, A005279, A196020, A236104, A235791, A237048, A237270, A237271, A237591, A237593, A239657, A244050, A245092, A250070, A261699, A279387, A279388, A279391.

Formula

a(n) = A001227(A250070(n)).