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!)
A127192 Triangle, square of A054523; row sums = A018804. 2
1, 2, 1, 4, 0, 1, 5, 2, 0, 1, 8, 0, 0, 0, 1, 8, 4, 2, 0, 0, 1, 12, 0, 0, 0, 0, 0, 1, 8, 4, 2, 0, 0, 1, 12, 0, 0, 0, 0, 0, 1, 12, 5, 0, 2, 0, 0, 0, 1, 16, 0, 4, 0, 0, 0, 0, 0, 1, 16, 8, 0, 0, 2, 0, 0, 0, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A018804: (1, 3, 5, 8, 9, 15,...), Sum of gcd(k,n) for 1<= k <= n. Left column = A029935: (1, 2, 4, 5, 8, 8, 12, 12,...). A127192 * d(n) = d(n) * n, or A127192 * A000005 = A038040 = (1, 4, 6, 12, 10, 24, 14,...).

LINKS

Table of n, a(n) for n=1..68.

FORMULA

Triangle, Square of A054523 By columns, parsed terms of A029935 interspersed with (k-1) zeros.

EXAMPLE

First few rows of the triangle are:

1;

2, 1;

4, 0, 1;

5, 2, 0, 1;

8, 0, 0, 0, 1;

8, 4, 2, 0, 0, 1;

12, 0, 0, 0, 0, 0, 1;

12, 5, 0, 2, 0, 0, 0, 1;

16, 0, 4, 0, 0, 0, 0, 0, 1;

...

CROSSREFS

Cf. A029935, A018804, A054523, A000005, A038040.

Sequence in context: A016585 A309054 A143316 * A122141 A091604 A200192

Adjacent sequences:  A127189 A127190 A127191 * A127193 A127194 A127195

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Jan 07 2007

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 April 9 07:41 EDT 2020. Contains 333344 sequences. (Running on oeis4.)