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A127504

Triangle T(n,k) = phi(n) if k|n, =0 otherwise.

1, 1, 1, 2, 0, 2, 2, 2, 0, 2, 4, 0, 0, 0, 4, 2, 2, 2, 0, 0, 2, 6, 0, 0, 0, 0, 0, 6, 4, 4, 0, 4, 0, 0, 0, 4, 6, 0, 6, 0, 0, 0, 0, 0, 6, 4, 4, 0, 0, 4, 0, 0, 0, 0, 4

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,4

LINKS

Table of n, a(n) for n=1..55.

FORMULA

T(n,k) = A000010(n)*A051731(n,k), 1<=k<=n.

EXAMPLE

First few rows of the triangle are:

1, 1;

2, 0, 2;

2, 2, 0, 2;

4, 0, 0, 0, 4;

2, 2, 2, 0, 0, 2;

6, 0, 0, 0, 0, 0, 6;

4, 4, 0, 4, 0, 0, 0, 4;

...

CROSSREFS

Cf. A051731, A062355 (row sums), A000010 (phi).

Sequence in context: A292118 A277486 A102395 * A321665 A329321 A334239

Adjacent sequences: A127501 A127502 A127503 * A127505 A127506 A127507

KEYWORD

nonn,tabl,easy

AUTHOR

Gary W. Adamson, Jan 17 2007

STATUS

approved