A115215 Sequence obtained by reading the triangles shown below by diagonals.

1, 1, 3, 2, 1, 3, 6, 2, 5, 4, 1, 3, 6, 10, 2, 5, 9, 4, 8, 7, 1, 3, 6, 10, 15, 2, 5, 9, 14, 4, 8, 13, 7, 12, 11, 1, 3, 6, 10, 15, 21, 2, 5, 9, 14, 20, 4, 5, 8, 13, 19, 7, 12, 18, 11, 17, 16, 1, 3, 6, 10, 15, 21, 28, 2, 5, 9, 14, 20, 27, 4, 8, 13, 19, 26, 7, 12, 18, 25, 11, 17, 24, 16, 23, 22

Offset

1,3

Links

Table of n, a(n) for n=1..85.

Example

1
1
2 3
1
2 3
4 5 6
1
2 3
4 5 6
7 8 9 10
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15

Crossrefs

See A124171 for another version.

Sequence in context: A244477 A035572 A325531 * A335012 A158275 A147750

Adjacent sequences: A115212 A115213 A115214 * A115216 A115217 A115218

Keyword

nonn

Author

Colm Mulcahy, Dec 05 2006

Extensions

More terms from Jonathan R. Love (japanada11(AT)yahoo.ca), Mar 07 2007

Status

approved