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.

Showing 1-3 of 3 results.

A218789 Partial sums of A218618.

Original entry on oeis.org

0, 1, 0, 1, 0, 3, 4, 3, 6, 11, 10, 11, 10, 13, 18, 17, 10, 11, 12, 15, 16, 15, 18, 23, 22, 15, 16, 17, 20, 13, 14, 15, 10, 11, 6, 3, 2, 3, 2, 5, 10, 9, 2, 3, 4, 7, 0, 1, 2, -3, -2, -7, -10, -11, -18, -17, -16, -21, -20, -9, -8, -7, 6, 7, 2, 1, 4, 5, 4, 7, 12
Offset: 0

Views

Author

Antti Karttunen, Dec 03 2012

Keywords

Comments

The term a(n) indicates approximately the "balance" of the binary beanstalk (cf. A179016) at n steps up from the root, which in turn has repercussions for the sequences such as A218542 and A218543.

Crossrefs

A218785 Partial sums of absolute values of A218618.

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 8, 9, 12, 17, 18, 19, 20, 23, 28, 29, 36, 37, 38, 41, 42, 43, 46, 51, 52, 59, 60, 61, 64, 71, 72, 73, 78, 79, 84, 87, 88, 89, 90, 93, 98, 99, 106, 107, 108, 111, 118, 119, 120, 125, 126, 131, 134, 135, 142, 143, 144, 149, 150, 161, 162, 163
Offset: 0

Views

Author

Antti Karttunen, Dec 03 2012

Keywords

Comments

The term a(n) tells how many nodes there are in total in all side-trees ("tendrils") encountered (see A213730) after we have walked n steps up along the infinite stem of the binary beanstalk, A179016.

Crossrefs

Cf. A218789.

A230407 Absolute value of a(n) tells the size of the n-th side-tree ("tendril", A230430(n)) in the factorial beanstalk; the sign tells on which side of the infinite trunk (A219666) it is.

Original entry on oeis.org

0, -1, 1, 3, -5, -1, 3, 1, 3, -5, -1, 7, -1, -5, -1, -5, 5, 5, -5, -11, 1, 3, -11, 1, -3, 3, 1, 3, -5, -1, 7, -1, -5, -1, -5, 5, 5, -5, -11, 1, 3, -21, 1, -3, -3, 9, 1, -1, -5, -1, -5, 5, 5, -5, -11, 1, 3, -21, 1, -3, -3, -11, -1, -9, -3, 5, 5, -5, -11, 1, 3
Offset: 0

Views

Author

Antti Karttunen, Nov 10 2013

Keywords

Comments

Positive and negative terms correspond to the tendrils that sprout respectively at the left and right sides of the infinite trunk, when the factorial beanstalk is drawn with the lesser numbers branching to the left. The absolute values give the sizes of those tendrils, with all nodes included: The leaves, the internal vertices as well as the root itself (which is at A230430(n)).
Here a(0) = 0 is a special case, as the infinite trunk starts to grow from its child 1, while the other child is 0 itself. (For both k=0 or k=1 it is true that A219651(k)=0).
This sequence relates to the factorial base representation (A007623) in the same way as A218618 relates to the binary system.

Crossrefs

Partial sums: A230408, A230409.

Programs

Formula

a(n) = ((-1)^A230430(n)) * A230427(A230430(n)).
Showing 1-3 of 3 results.