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 1-2 of 2 results.

A236626 Sum of all parts of all overcompositions of n.

Original entry on oeis.org

2, 8, 36, 104, 300, 864, 2268, 5824, 14418, 35760, 85888, 204816, 479804, 1113280, 2560560, 5836704, 13209612, 29690208, 66332572, 147350880, 325780056, 716862256, 1571067072, 3429697920, 7461222850, 16178111560, 34973640108, 75392349648
Offset: 1

Views

Author

Omar E. Pol, Feb 01 2014

Keywords

Comments

For the definition of overcomposition see A236002.
The equivalent sequence for overpartitions is A235793.

Examples

			For n = 3 the 12 overcompositions of 3 are [3], [3'], [1, 2], [1', 2], [1, 2'], [1', 2'], [2, 1], [2', 1], [2, 1'], [2', 1'], [1, 1, 1], [1', 1, 1], hence the sum of all parts is 3+3+1+2+1+2+1+2+1+2+2+1+2+1+2+1+2+1+1+1+1+1+1+1 = 3*12 = 36, so a(3) = 36.
		

Crossrefs

Formula

a(n) = n*A236002(n).

A236628 Triangle read by rows in which T(n,k) is the number of parts in the k-th region of the set of overcompositions of n, with overcompositions in colexicographic order.

Original entry on oeis.org

2, 2, 4, 2, 6, 4, 12, 2, 6, 4, 14, 4, 6, 4, 26
Offset: 1

Views

Author

Omar E. Pol, Feb 01 2014

Keywords

Comments

Right border gives A236002, n >= 1.
Row sums give A236625, n >= 1.

Examples

			Written as an irregular triangle in which row n has length 2^n the sequence begins:
2;
2, 4;
2, 6, 4, 12;
2, 6, 4, 14, 4, 6, 4, 26;
...
For n = 3 the diagram shows the four regions of the overcompositions of 3, with overcompositions in colexicographic order.
------------------------------------------------
.  Diagram of            Regions of the diagram
overcompositions        ------------------------
.    of 3                k: 1     2   3       4
------------------------------------------------
.    _ _ _                  _     _           _
1   |.| | |                |.|   | |         | |
2   |_| | |                |_|  _| |         | |
3   |  .|.|                    |  .|         |.|
4   |   |.|                    |   |         |.|
5   |  .| |                    |  .|         | |
6   |_ _| |                    |_ _|  _     _| |
7   |.|  .|                          |.|   |  .|
8   | |  .|                          | |   |  .|
9   |.|   |                          |.|   |   |
10  |_|   |                          |_|  _|   |
11  |    .|                              |    .|
12  |_ _ _|                              |_ _ _|
...
Number of parts.........:   2     6   4      12
.
Every row of every region contains only one part.
		

Crossrefs

Showing 1-2 of 2 results.