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.

A228720 Number of partitions in the first n compositions of j, according with the ordering of A228525, if 1<=n<=2^(j-1).

Original entry on oeis.org

1, 2, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15
Offset: 1

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Author

Omar E. Pol, Aug 30 2013

Keywords

Comments

For a program, see A228525.

Examples

			For n = 13 there are only six partitions in the first 13 rows of the list of compositions of any integer >= 5, so a(13) = 6.
---------------------------------------------------------
.               |          Compositions of j
.               |
n  a(n) A228354 | 1    2     3       4         5
---------------------------------------------------------
.
1   1  *   1      1    1+1   1+1+1   1+1+1+1   1+1+1+1+1
2   2  *   2           2     2+1     2+1+1     2+1+1+1
3   2                        1+2     1+2+1     1+2+1+1
4   3  *   4                 3       3+1       3+1+1
5   3                                1+1+2     1+1+2+1
6   4  *   6                         2+2       2+2+1
7   4                                1+3       1+3+1
8   5  *   8                         4         4+1
9   5                                          1+1+1+2
10  5                                          2+1+2
11  5                                          1+2+2
12  6  *  12                                   3+2
13  6                                          1+1+3
14  6                                          2+3
15  6                                          1+4
16  7  *  16                                   5
...
		

Crossrefs

Where records occur here are in A228354.

Formula

a(2^(n-1)) = A000041(n), n >= 1.