A230408 -id:A230408 - cp's OEIS frontend

A230409 Partial sums of A230407.

0, -1, 0, 3, -2, -3, 0, 1, 4, -1, -2, 5, 4, -1, -2, -7, -2, 3, -2, -13, -12, -9, -20, -19, -22, -19, -18, -15, -20, -21, -14, -15, -20, -21, -26, -21, -16, -21, -32, -31, -28, -49, -48, -51, -54, -45, -44, -45, -50, -51, -56, -51, -46, -51, -62, -61, -58, -79

Offset: 0

Antti Karttunen, Nov 10 2013

sign

The term a(n) indicates approximately the "balance" of the factorial beanstalk (cf. A219666) at n steps up from the root, which in turn correlates with the behavior of such sequences as A219662 and A219663.
This sequence relates to the factorial base representation (A007623) in the same way as A218789 relates to the binary system.
Question: When will a negative term occur next time, after a(251) = -41 ?

Antti Karttunen, Table of n, a(n) for n = 0..21622

Cf. A230407 & A230408, A219662 & A219663.

a(0) = 0, a(n) = a(n-1) + A230407(n).

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

Antti Karttunen, Nov 10 2013

sign

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.

Antti Karttunen, Table of n, a(n) for n = 0..3149

Partial sums: A230408, A230409.

(define (A230407 n) (* (expt -1 (A230430 n)) (A230427 (A230430 n))))

a(n) = ((-1)^A230430(n)) * A230427(A230430(n)).

A255333 Partial sums of A255330.

Original entry on oeis.org

1, 3, 3, 7, 8, 8, 15, 15, 18, 19, 19, 24, 26, 32, 32, 38, 38, 41, 42, 42, 47, 49, 61, 61, 63, 68, 68, 72, 74, 80, 80, 86, 86, 89, 90, 90, 95, 97, 109, 109, 111, 118, 119, 131, 135, 135, 137, 142, 142, 146, 148, 160, 160, 162, 167, 167, 171, 173, 179, 179, 185, 185, 188, 189, 189, 194

Offset: 0

Antti Karttunen, Feb 21 2015

nonn

Antti Karttunen, Table of n, a(n) for n = 0..8590

Cf. A000079, A000225, A255061, A255062, A255330, A255332.

Analogous sequences: A218785, A230408.

a(0) = 1; for n >= 1: a(n) = a(n-1) + A255330(n).
Other identities:
a(A255061(n)-1) = A000225(n) - A255062(n) for all n >= 2.
Equally: a(A255061(n)-1) + A255062(n) + 1 = A000079(n) = 2^n for all n >= 2.

cp's OEIS Frontend

A230409 Partial sums of A230407.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula

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.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

Scheme

Formula

A255333 Partial sums of A255330.

Views

Author

Keywords

Links

Crossrefs

Formula