login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137587 Triangle read by rows: A051731 * A026794. 2
1, 2, 1, 3, 0, 1, 5, 2, 0, 1, 6, 1, 0, 0, 1, 11, 3, 2, 0, 0, 1, 12, 2, 1, 0, 0, 0, 1, 20, 6, 1, 2, 0, 0, 0, 1, 25, 4, 3, 1, 0, 0, 0, 0, 1, 37, 9, 2, 1, 2, 0, 0, 0, 0, 1, 43, 8, 3, 1, 1, 0, 0, 0, 0, 0, 1, 70, 16, 6, 3, 1, 2, 0, 0, 0, 0, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

That is, regard A051731 and A026794 as lower triangular square matrices and multiply them, then take the lower triangle of the product,

Left column = A083710 starting (1, 2, 3, 5, 6, 11, 12,...). Row sums = A047968.

LINKS

Table of n, a(n) for n=1..78.

FORMULA

Inverse mobius transform of the partition triangle, A026794

EXAMPLE

First few rows of the triangle are:

.1;

.2, 1;

.3, 0, 1;

.5, 2, 0, 1;

.6, 1, 0, 0, 1;

.11, 3, 2, 0, 0, 1;

.12, 2, 1, 0, 0, 0, 1;

.20, 6, 1, 2, 0, 0, 0, 1;

.25, 4, 3, 1, 0, 0, 0, 0, 1;

....

CROSSREFS

Cf. A026794, A051731, A083710, A047968.

Sequence in context: A195665 A096798 A158902 * A168021 A137639 A239631

Adjacent sequences:  A137584 A137585 A137586 * A137588 A137589 A137590

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jan 27 2008

EXTENSIONS

Typo in 9th row corrected by M. F. Hasler, Jun 08 2009

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 22 09:35 EST 2017. Contains 295076 sequences.