A238384 Triangle of numbers related to A075535.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 3, 2, 1, 1, 1, 1, 2, 3, 3, 2, 1, 1, 1, 1, 2, 3, 4, 3, 2, 1, 1, 1, 1, 2, 3, 4, 4, 3, 2, 1, 1, 1, 1, 2, 3, 4, 6, 4, 3, 2, 1, 1, 1, 1, 2, 3, 4, 6, 6, 4, 3, 2, 1, 1, 1, 1, 2, 3, 4, 6

Offset: 0

Author

Philippe Deléham, Feb 25 2014

Keywords

• easy
• nonn
• tabl

Comments

Triangle read by rows; each row is an initial segment of the terms of A075535 followed by its reflection.

Examples

			Triangle begins:
1;
1, 1;
1, 1, 1;
1, 1, 1, 1;
1, 1, 2, 1, 1;
1, 1, 2, 2, 1, 1;
1, 1, 2, 3, 2, 1, 1;
1, 1, 2, 3, 3, 2, 1, 1;
1, 1, 2, 3, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 6, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 6, 6, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 6, 8, 6, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 6, 8, 8, 6, 4, 3, 2, 1, 1;
1, 1, 2, 3, 4, 6, 8,11, 8, 6, 4, 3, 2, 1, 1;
		

Crossrefs

Cf. A075535.

Formula

T(2n,n) = A075535(n+1).

Sum_{k=0..n} T(n,k) = A075535(n+2).