cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A153239 Balance of binary trees as ordered by A014486: number of vertices in the right subtree minus number of vertices in the left subtree.

Original entry on oeis.org

0, 0, 1, -1, 2, 2, 0, -2, -2, 3, 3, 3, 3, 3, 1, 1, -1, -3, -3, -1, -3, -3, -3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 2, 2, 2, 2, 2, 0, 0, -2, -4, -4, -2, -4, -4, -4, 0, 0, -2, -4, -4, -2, -4, -4, -4, -2, -4, -4, -4, -4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5
Offset: 0

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Author

Antti Karttunen, Dec 21 2008

Keywords

Comments

Note that for all n, Sum_{i=A014137(n)}^A014138(n) a(i) = 0.

Examples

			A014486(19) encodes the following binary tree:
.\/
..\/.\/
...\./
Because the subtree at the right contains just one internal node and the subtree at the left contains two, we have a(19) = 1-2 = -1.
		

Crossrefs

A153243 gives the positions of zeros. Cf. A153240, A153241.