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 1-6 of 6 results.

A218611 Positions in A218787 and A218788 of successive distinct values.

Original entry on oeis.org

1, 5, 9, 16, 32, 59, 62, 115, 118, 208, 212, 213, 384, 389, 649, 654, 686, 703, 708, 716, 720, 723, 1310, 1326, 1328, 1338, 2236, 2369, 2422, 2432, 2452, 2458, 2466, 2476, 2486, 2488, 4545, 4601, 4625, 4627, 4637, 7811, 7817, 7819, 7826, 8287, 8511, 8526, 8631
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2012

Keywords

Comments

The terms give the positions to A213730 where for the first time a new, never-before-encountered sidetree ("tendril") appears from the side of the infinite beanstalk. See A179016, A218609 and also A218612.

Crossrefs

A218612 Numbers which are the roots of distinct not-previously-encountered side-trees ("tendrils") sprouting from the side of the infinite beanstalk (see A213730).

Original entry on oeis.org

2, 10, 22, 47, 105, 208, 224, 471, 486, 943, 966, 974, 1934, 1972, 3509, 3546, 3765, 3893, 3930, 3995, 4027, 4049, 7912, 8041, 8058, 8146, 14291, 15315, 15738, 15827, 15995, 16040, 16122, 16211, 16312, 16334, 31694, 32207, 32440, 32462, 32568, 57145, 57208
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2012

Keywords

Crossrefs

A superset of A218548. Cf. A218611, A218613.

Programs

Formula

a(n) = A213730(A218611(n)).

A218786 The sizes of the "tendrils" (finite side-trees sprouting at A213730, A218787) of infinite beanstalk (A179016).

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 1, 2, 0, 0, 0, 1, 2, 0, 3, 0, 0, 1, 0, 0, 1, 2, 0, 3, 0, 0, 1, 3, 0, 0, 2, 0, 2, 1, 0, 0, 0, 1, 2, 0, 3, 0, 0, 1, 3, 0, 0, 2, 0, 2, 1, 0, 3, 0, 0, 2, 0, 5, 0, 0, 6, 0, 2, 0, 1, 0, 0, 1, 2, 0, 3, 0, 0, 1, 3, 0, 0, 2, 0, 2, 1, 0, 3, 0, 0, 2
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2012

Keywords

Examples

			The first four tendrils of the beanstalk sprout at 2, 5, 6 and 9, (the first four nonzero terms of A213730) which are all leaves (i.e., in A055938), thus the first four terms of this sequence are all 0's. The next term A213730(5)=10, which is not leaf, but branches to two leaf-branches (12 and 13, as with both we have: 12-A000120(12)=10 and 13-A000120(13)=10, and both 12 and 13 are found from A055938, so the tendril at 10 is a binary tree of one internal vertex (and two leaves), i.e., \/, thus a(5)=1.
		

Crossrefs

Equally, a(n) = A072643(A218787(n)) = A072643(A218788(n)). Cf. A218613, A218603, A218604.

Programs

Formula

a(n) = A213726(A213730(n))-1.

A218609 Distinct values of A218787 in the order of appearance.

Original entry on oeis.org

0, 1, 2, 8, 3, 60, 172, 12, 20, 49, 54, 3016, 10096, 125744802, 101035235, 25, 1358590114, 40796719636668219, 70, 19049, 1770, 18, 7, 16261, 82682568533587123, 17, 36, 307, 315899951699378231, 3871315398, 15215587727307698, 59, 9097520004151634187729920190004140
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2012

Keywords

Comments

a(n) = A014486-index for the n-th tendril of the infinite beanstalk (A179016), which has not been encountered before, constructed with lesser numbers coming to the left, and larger to the right hand side of each branch.

Crossrefs

These are the mirror-images of binary trees given in A218610, i.e. a(n) = A057163(A218610(n)). A218613 gives the sizes of these trees. Cf. A218611.

Programs

Formula

a(n) = A218787(A218611(n)).

A218610 Distinct values of A218788 in the order of appearance.

Original entry on oeis.org

0, 1, 3, 4, 2, 37, 110, 18, 11, 32, 33, 4755, 16127, 73542063, 97105360, 62, 1306632183, 39288694215537689, 193, 8150, 719, 12, 5, 13505, 246941338376004599, 13, 45, 407, 944077158106260984, 4975012595, 5738426278308884, 26, 27439590092251146768825651348524279
Offset: 1

Views

Author

Antti Karttunen, Nov 11 2012

Keywords

Comments

a(n) = A014486-index for the n-th tendril of the infinite beanstalk (A179016), which has not been encountered before, constructed with lesser numbers coming to the right, and larger to the left hand side of each branch.

Crossrefs

These are the mirror-images of binary trees given in A218609, i.e. a(n) = A057163(A218609(n)). A218613 gives the sizes of these trees. Cf. A218611.

Programs

Formula

a(n) = A218788(A218611(n)).

A218618 Absolute value of a(n) tells the size of the n-th side-tree ("tendril", A213730(n)) in the binary beanstalk; the sign tells on which side of the infinite trunk (A179016) it is.

Original entry on oeis.org

0, 1, -1, 1, -1, 3, 1, -1, 3, 5, -1, 1, -1, 3, 5, -1, -7, 1, 1, 3, 1, -1, 3, 5, -1, -7, 1, 1, 3, -7, 1, 1, -5, 1, -5, -3, -1, 1, -1, 3, 5, -1, -7, 1, 1, 3, -7, 1, 1, -5, 1, -5, -3, -1, -7, 1, 1, -5, 1, 11, 1, 1, 13, 1, -5, -1, 3, 1, -1, 3, 5, -1, -7, 1, 1, 3
Offset: 0

Views

Author

Antti Karttunen, Dec 03 2012

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 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: A213730(n).

Crossrefs

Partial sums: A218785, A218789. Cf. also A218786, A218613.

Programs

Formula

a(n) = -1^A213730(n) * A213727(A213730(n)).
Showing 1-6 of 6 results.