login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A122401 Subsequence of A074139 omitting values derived from partitions with a part of size 1. 2
1, 3, 4, 5, 9, 6, 12, 7, 15, 16, 27, 8, 18, 20, 36, 9, 21, 24, 25, 45, 48, 81, 10, 24, 28, 30, 54, 60, 64, 108, 11, 27, 32, 35, 63, 36, 72, 75, 80, 135, 144, 243, 12, 30, 36, 40, 72, 42, 84, 90, 96, 162, 100, 180, 192, 324, 13, 33, 40, 45, 81, 48, 96, 49, 105, 112, 189, 108, 120, 216, 125, 225, 240, 405, 256, 432, 729, 14, 36, 44, 50, 90, 54 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

When viewed as a table, row sums are given by sequence A079274.

Corresponds to members of A036035 which are also powerful numbers (A001694).

LINKS

Table of n, a(n) for n=0..82.

EXAMPLE

The two cyclic partitions of five are 5 and 3+2 yielding (5+1)=6 and (3+1)*(2+1) = 4*3 = 12

The array begins

1

(empty)

3

4

5 9

6 12

7 15 16 27

8 18 20 36

MAPLE

A122401_row := proc(n)

    local e, a, L;

    L := [] ;

    for e in ListTools[Reverse](partition(n)) do

        if member(1, e) then

            ;

        else

            a := 1;

            for p in e do

                a := a*(p+1) ;

            end do:

            L := [op(L), a] ;

        end if;

    end do:

    L ;

end proc:

seq(A122401_row(i), i=0..15); # R. J. Mathar, Aug 28 2018

CROSSREFS

Cf. A122172 A079274 A122402, A316532.

Sequence in context: A330577 A020863 A215496 * A122403 A302653 A300738

Adjacent sequences:  A122398 A122399 A122400 * A122402 A122403 A122404

KEYWORD

easy,nonn,tabf

AUTHOR

Alford Arnold, Sep 01 2006

EXTENSIONS

Extended by R. J. Mathar, Aug 28 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 28 14:47 EDT 2020. Contains 334684 sequences. (Running on oeis4.)