A282934 Concatenation of the numbers of elements of P{d_1}, P{d_2}, P{d_3}, ..., P{d_n}; where P{d_n} denote the power set of the set of divisors of n ordered by the size of the subsets, and in each subset, following the increasing order.

1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 2, 2, 2, 3, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 1, 1, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 1, 1, 1, 2, 2, 2, 3, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2

Offset

1,4

Links

Table of n, a(n) for n=1..87.

Example

Rows with power sets of set of divisors of n (without nonempty sets):
{1};
{1}, {2}, {1, 2};
{1}, {3}, {1, 3};
{1}, {2}, {4}, {1, 2}, {1, 4}, {2, 4}, {1, 2, 4};
...
Rows with the numbers of elements of these subsets:
1;
1, 1, 2;
1, 1, 2;
1, 1, 1, 2, 2, 2, 3;
...
Concatenation: 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 2, 2, 2, 3, ...

Mathematica

Table[Length /@ Rest[Subsets[Divisors[n]]], {n, 1, 12}] // Flatten (* Jean-François Alcover, Nov 13 2017 *)

Crossrefs

Cf. A282903, A282935, A282936.

Sequence in context: A073204 A322286 A248641 * A273619 A327522 A034003

Adjacent sequences: A282931 A282932 A282933 * A282935 A282936 A282937

Keyword

nonn

Author

Jaroslav Krizek, Feb 25 2017

Status

approved