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.

User: Christopher Landauer

Christopher Landauer's wiki page.

Christopher Landauer has authored 4 sequences.

A338054 "Early" terms in A336957, arranged in increasing order.

Original entry on oeis.org

6, 12, 14, 15, 18, 20, 21, 22, 26, 28, 33, 34, 35, 38, 39, 40, 42, 44, 45, 46, 50, 51, 52, 55, 56, 57, 58, 62, 63, 65, 68, 69, 70, 74, 75, 76, 77, 80, 82, 84, 85, 87, 91, 93, 95, 96, 98, 99, 100, 102, 104, 105, 108, 110, 111, 112, 115, 116, 117, 118, 119, 122, 123, 124, 126, 129
Offset: 1

Views

Author

Scott R. Shannon and N. J. A. Sloane, Oct 11 2020, following a suggestion from Christopher Landauer

Keywords

Comments

A term A336957(k) is early if A336957(k) > k; punctual if A336957(k) = k (see A338050); and late if A336957(k) < k.
It appears that the majority of terms are late.

Crossrefs

Cf. A336957, A338050, A338051, A338053.

A338053 "Early" terms in A336957, in order of appearance.

Original entry on oeis.org

6, 15, 35, 14, 12, 33, 55, 18, 21, 77, 22, 20, 45, 39, 26, 28, 63, 51, 34, 38, 57, 69, 46, 40, 65, 91, 42, 85, 119, 56, 75, 95, 76, 87, 145, 50, 44, 99, 93, 62, 52, 117, 105, 70, 58, 261, 111, 74, 68, 153, 123, 82, 80, 115, 161, 84, 155, 217, 98, 129, 215, 100, 141, 235, 110, 147, 133
Offset: 1

Views

Author

Scott R. Shannon and N. J. A. Sloane, Oct 11 2020, following a suggestion from Christopher Landauer

Keywords

Comments

A term A336957(k) is early if A336957(k) > k; punctual if A336957(k) = k (see A338050); and late if A336957(k) < k.
It appears that the majority of terms are late.

Crossrefs

Cf. A336957, A338050, A338051, A338054.

A094098 Number of divisor chains of length n in which the first term is a divisor of n(n+1)/2 ("cyclic" divisor chains).

Original entry on oeis.org

1, 0, 2, 0, 2, 0, 3, 0, 5, 0, 6, 0, 6, 0, 147, 1, 22, 2, 27, 165, 519, 0, 516, 2021, 1912, 506, 45658, 514, 7308, 1535, 30746, 68918, 145920, 1370
Offset: 1

Views

Author

Christopher Landauer, May 04 2004

Keywords

Comments

A divisor chain of length n is an arrangement of 1..n such that each term is a divisor of the sum of the preceding terms.

Crossrefs

Cf. A067957, A094097, A094099.

Extensions

a(29)-a(34) from John W. Layman, May 07 2004

A094099 Number of divisor chains of length 2n+1 which are both cyclic and anchored.

Original entry on oeis.org

1, 1, 1, 1, 4, 2, 4, 47, 6, 6, 462, 372, 1589, 20896, 4118, 12815, 130528, 1942045, 163775, 18340336, 5065878, 3607762
Offset: 0

Views

Author

Christopher Landauer, May 04 2004

Keywords

Comments

A divisor chain of length n is an arrangement of 1..n such that each term is a divisor of the sum of the preceding terms.

Crossrefs

Cf. A067957, A094097, A094098, A094099.

Formula

a(n) = A094097(2n+1). - Martin Fuller, Jul 18 2025

Extensions

a(14)-a(21) from A094097 by Martin Fuller, Jul 18 2025

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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