A143620 Triangle read by rows, square of A054521, 1<=k<=n.

1, 1, 0, 2, 0, 0, 2, 1, 0, 0, 4, 1, 1, 0, 0, 2, 1, 1, 1, 0, 0, 6, 2, 2, 1, 1, 0, 0, 4, 3, 2, 2, 1, 1, 0, 0, 6, 2, 4, 2, 2, 1, 1, 0, 0, 4, 3, 1, 2, 2, 1, 1, 1, 0, 0, 10, 4, 5, 3, 4, 1, 3, 1, 1, 0, 0, 4, 3, 3, 3, 2, 2, 1, 1, 1, 1, 0, 0

Offset

1,4

Comments

Left border = phi(n), A000010.

Row sums = A053570: (1, 1, 2, 3, 6, 5, 12, 13,...).

Links

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

Formula

Triangle read by rows, square of A054521, 1<=k<=n

Example

First few rows of the triangle =
1;
1, 0;
2, 0, 0;
2, 1, 0, 0;
4, 1, 1, 0, 0;
2, 1, 1, 1, 0, 0;
6, 2, 2, 1, 1, 0, 0;
4, 3, 2, 2, 1, 1, 0, 0;
6, 2, 4, 2, 2, 1, 1, 0, 0;
...

Crossrefs

Cf. A054521, A000010, A053570.

Sequence in context: A238354 A353836 A161364 * A291529 A366981 A236417

Adjacent sequences: A143617 A143618 A143619 * A143621 A143622 A143623

Keyword

nonn,tabl

Author

Gary W. Adamson, Aug 27 2008

Status

approved