A143595 Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); 1<=k<=n.

1, 2, 2, 3, 4, 2, 4, 6, 4, 2, 5, 8, 6, 4, 2, 6, 10, 8, 6, 4, 2, 7, 12, 10, 8, 6, 4, 2, 8, 14, 12, 10, 8, 6, 4, 2, 9, 16, 14, 12, 10, 8, 6, 4, 2, 10, 18, 16, 14, 12, 10, 8, 6, 4, 2, 11, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2

Offset

1,2

Comments

Row sums = n^2.

The linear sequence A056944 is more appropriately a triangle, (reversal of A143595).

Links

Table of n, a(n) for n=1..66.

Formula

Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); i.e. (1; 1,2; 1,2,2;...). A000012 = an infinite lower triangular matrix with all 1's. 1<=k<=n

Example

First few rows of the triangle =
1;
2, 2;
3, 4, 2;
4, 6, 4, 2;
5, 8, 6, 4, 2;
6, 10, 8, 6, 4, 2;
7, 12, 10, 8, 6, 4, 2;
...

Crossrefs

Cf. A056944.

Sequence in context: A194331 A372606 A290600 * A211702 A208521 A209570

Adjacent sequences: A143592 A143593 A143594 * A143596 A143597 A143598

Keyword

nonn,tabl

Author

Gary W. Adamson, Aug 26 2008

Status

approved