A164002 Triangle read by rows in which each row contains a finite triangle as shown below.

1, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 2, 2, 2, 3, 2, 1, 2, 2, 1, 1, 2, 2, 2, 3, 2, 2, 3, 3, 2, 1, 2, 2, 2, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 3, 2, 3, 4, 3, 2, 1, 2, 3, 3, 2, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 5, 4, 3, 2, 3, 4, 4, 3, 2, 1, 2, 3, 3, 3, 2, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 5, 4, 3, 3, 4, 5, 5, 4, 3

Offset

1,6

Comments

See also A159800.

Links

Table of n, a(n) for n=1..105.

Example

The main triangle begins:
1
1,1,1
1,2,2,1,2,1
1,2,2,2,3,2,1,2,2,1
1,2,2,2,3,2,2,3,3,2,1,2,2,2,1
1,2,2,3,3,3,3,4,4,3,2,3,4,3,2,1,2,3,3,2,1
1,2,2,3,3,3,3,4,4,3,3,4,5,4,3,2,3,4,4,3,2,1,2,3,3,3,2,1
1,2,2,3,3,3,3,4,4,3,3,4,5,4,3,3,4,5,5,4,3,2,3,4,4,4,3,2,1,2,3,3,3,3,2,1
In which row 1 contains a vertex, only:
1
Row 2 contains the triangle:
1
1,1
Row 3 contains the triangle:
1
2,2
1,2,1
Row 4 contains the triangle:
1
2,2
2,3,2
1,2,2,1
Row 5 contains the triangle:
1
2,2
2,3,2
2,3,3,2
1,2,2,2,1
Row 6 contains the triangle:
1
2,2
3,3,3
3,4,4,3
2,3,4,3,2
1,2,3,3,2,1
Row 7 contains the triangle:
1
2,2
3,3,3
3,4,4,3
3,4,5,4,3
2,3,4,4,3,2
1,2,3,3,3,2,1
Row 8 contains the triangle:
1
2,2
3,3,3
3,4,4,3
3,4,5,4,3
3,4,5,5,4,3
2,3,4,4,4,3,2
1,2,3,3,3,3,2,1
Row 9 contains the triangle:
1
2,2
3,3,3
4,4,4,4
4,5,5,5,4
4,5,6,6,5,4
3,4,5,6,5,4,3
2,3,4,5,5,4,3,2
1,2,3,4,4,4,3,2,1
Row 10 contains the triangle:
1
2,2
3,3,3
4,4,4,4
4,5,5,5,4
4,5,6,6,5,4
4,5,6,7,6,5,4
3,4,5,6,6,5,4,3
2,3,4,5,5,5,4,3,2
1,2,3,4,4,4,4,3,2,1
And so on...

Crossrefs

Cf. A159800, A163993, A163994.

Sequence in context: A270647 A261126 A097456 * A322156 A332278 A182596

Adjacent sequences: A163999 A164000 A164001 * A164003 A164004 A164005

Keyword

nonn,tabf

Author

Omar E. Pol, Nov 10 2009

Status

approved