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 1-5 of 5 results.

A276978 a(n) = (ceiling(n/2))^n.

Original entry on oeis.org

1, 1, 8, 16, 243, 729, 16384, 65536, 1953125, 9765625, 362797056, 2176782336, 96889010407, 678223072849, 35184372088832, 281474976710656, 16677181699666569, 150094635296999121, 10000000000000000000, 100000000000000000000, 7400249944258160101211
Offset: 1

Views

Author

Olivier Gérard, Sep 23 2016

Keywords

Comments

Functions from [n] to [n] with f(i) odd for all i.
Apart from initial term first differs from A132377 at a(9).
With a(1) = 0: AGM transform of A000035. See A368366 for the definition of the AGM transform. - Alois P. Heinz, Jan 24 2024

Crossrefs

Cf. A206344, A276979 (other similar classes of endofunctions).

Programs

  • Mathematica
    Table[Ceiling[n/2]^n, {n, 1, 21}]
  • PARI
    a(n)= ceil(n/2)^n; \\ Michel Marcus, Oct 08 2016

A206345 Number of solvable clock puzzles with n positions in Final Fantasy XIII-2.

Original entry on oeis.org

0, 1, 1, 13, 32, 507, 1998, 33136, 193995, 3426518, 27187715, 501668052, 5124675822
Offset: 1

Views

Author

Nathaniel Johnston, Feb 06 2012

Keywords

Comments

The sequence gives the number of ways of placing the integers 1, 2, ..., floor(n/2) (with repetition) in n spaces on a circle so that you can jump to every integer exactly once, and the distance you jump is equal to the integer you are currently standing on.
A206344 is a trivial upper bound.
This is the same as A206346, except clock puzzles that are rotations or reflections of each other are counted as distinct.

Examples

			A solvable clock puzzle in the n = 6 case arises from the following integers (placed clockwise around a circle): 1, 3, 3, 2, 1, 3. If we label the positions 0, 1, 2, 3, 4, 5, then a solution to this puzzle is the following sequence of positions: 0, 1, 4, 3, 5, 2.
		

Crossrefs

Extensions

a(10) from Nathaniel Johnston, Feb 07 2012
a(11)-a(13) from Bert Dobbelaere, Apr 28 2021

A206346 Number of solvable clock puzzles with n positions in Final Fantasy XIII-2, up to rotation and reflection.

Original entry on oeis.org

0, 1, 1, 4, 8, 58, 177, 2196, 11091, 172522, 1239350, 20916154, 197149146
Offset: 1

Views

Author

Nathaniel Johnston, Feb 06 2012

Keywords

Comments

Equals the number of Hamiltonian directed graphs on n vertices with the properties that: (1) every vertex has outdegree 1 or 2; and (2) the vertices can be arranged in a circle so that the directed edges leaving each vertex are symmetric about that vertex (e.g., if there is a directed edge that points two vertices in the clockwise direction, then the other one must point two vertices in the counterclockwise direction).
The same as A206345, except clock puzzles that are simply rotations or reflections of each other are not counted multiple times.

Crossrefs

Extensions

a(6)-a(9) corrected, a(10)-a(13) added by Max Alekseyev, Jul 31 2025

A233203 a(n) = floor(n^n / 2^n).

Original entry on oeis.org

1, 0, 1, 3, 16, 97, 729, 6433, 65536, 756680, 9765625, 139312339, 2176782336, 36972058910, 678223072849, 13363461010158, 281474976710656, 6311342330065435, 150094635296999121, 3773536025353076151, 100000000000000000000, 2785962590401641140642, 81402749386839761113321
Offset: 0

Views

Author

Alex Ratushnyak, Dec 05 2013

Keywords

Examples

			a(5) = floor(5^5 / 2^5) = floor(3125 / 32) = 97.
		

Crossrefs

Cf. A000079, A000312, A178537 (n^n mod 2^n for odd n), A206344.
Bisection gives: A062206 (even part).

Programs

Formula

a(n) = floor((n/2)^n).

A276979 a(n) = (floor(n/2)+1)^n.

Original entry on oeis.org

1, 4, 8, 81, 243, 4096, 16384, 390625, 1953125, 60466176, 362797056, 13841287201, 96889010407, 4398046511104, 35184372088832, 1853020188851841, 16677181699666569, 1000000000000000000, 10000000000000000000, 672749994932560009201
Offset: 1

Views

Author

Olivier Gérard, Sep 23 2016

Keywords

Comments

Functions from [n] to [n] with f(i) even or f(i) = 1 for all i.
Functions from [n] to [n] with f(i) odd or f(i) = n for all i.

Crossrefs

Programs

  • Mathematica
    Table[(Floor[n/2] + 1)^n, {n, 1, 20}]
  • PARI
    a(n) = (n\2 + 1)^n; \\ Michel Marcus, Oct 08 2016
Showing 1-5 of 5 results.