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A143613 Triangle read by rows, A051731 * A127368, 1<=k<=n. 1
1, 2, 0, 2, 2, 0, 3, 0, 3, 0, 2, 2, 3, 4, 0, 4, 2, 0, 0, 5, 0, 2, 2, 3, 4, 5, 6, 0, 4, 0, 6, 0, 5, 0, 7, 0, 3, 4, 0, 4, 5, 0, 7, 8, 0, 4, 2, 6, 4, 0, 0, 7, 0, 9, 0, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 0, 6, 2, 3, 0, 10, 0, 7, 0, 0, 0, 11, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Left border = d(n).

Row sums = A057661: (1, 2, 4, 6, 11, 11, 22, 22, 31,...).

LINKS

Table of n, a(n) for n=1..89.

FORMULA

Triangle read by rows, A051731 * A127368, 1<=k<=n. A051731 = the inverse Mobius transform. A127368 records the reduced residue system mod n, by rows.

EXAMPLE

First few rows of the triangle =

1;

2, 0;

2, 2, 0;

3, 0, 3, 0;

2, 2, 3, 4, 0;

4, 2, 0, 0, 5, 0;

2, 2, 3, 4, 5, 6, 0;

...

CROSSREFS

Cf. A127368, A051731, A057661, A000005.

Sequence in context: A127800 A035692 A308654 * A208955 A121363 A214258

Adjacent sequences:  A143610 A143611 A143612 * A143614 A143615 A143616

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Aug 27 2008

STATUS

approved

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Last modified July 22 05:47 EDT 2019. Contains 325213 sequences. (Running on oeis4.)