A141289 Triangle read by rows, n-th row = (n-2)-th row appended to the beginning of (n-1)-th row, + n.

1, 1, 2, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5, 1, 2, 1, 1, 2, 3, 4, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5, 6, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5, 1, 2, 1, 1, 2, 3, 4, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5, 6, 7

Offset

1,3

Comments

There are (1, 2, 4, 7, 12,...) terms per row where (0, 0, 1, 2, 4, 7, 12,...) = A000071 = Fibonacci numbers - 1.

Row sums = A001924: (1, 3, 7, 14, 26, 46,...)

Links

Table of n, a(n) for n=1..79.

Formula

Triangle read by rows, n-th row = (n-2)-th row appended to the beginning of (n-1)-th row, + n.

Example

First few rows of the triangle are:
1;
1, 2;
1, 1, 2, 3;
1, 2, 1, 1, 2, 3, 4;
1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5;
1, 2, 1, 1, 2, 3, 4, 1, 1, 2, 3, 1, 2, 1, 1, 2, 3, 4, 5, 6;
...
Row 4 = (1, 2, 1, 1, 2, 3, 4) = (row 2 appended to row 3, + 4); = (1, 2) appended to (1, 1, 2, 3), then 4.

Crossrefs

Cf. A000071, A001924.

Sequence in context: A180262 A161789 A109671 * A368878 A284271 A241915

Adjacent sequences: A141286 A141287 A141288 * A141290 A141291 A141292

Keyword

nonn,tabf

Author

Gary W. Adamson, Jun 22 2008

Status

approved