This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A228351 Triangle read by rows in which row n lists the compositions (ordered partitions) of n (see Comments lines for definition). 13
 1, 2, 1, 1, 3, 1, 2, 2, 1, 1, 1, 1, 4, 1, 3, 2, 2, 1, 1, 2, 3, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 5, 1, 4, 2, 3, 1, 1, 3, 3, 2, 1, 2, 2, 2, 1, 2, 1, 1, 1, 2, 4, 1, 1, 3, 1, 2, 2, 1, 1, 1, 2, 1, 3, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 6, 1, 5, 2, 4, 1, 1, 4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The representation of the compositions (for fixed n) is as lists of parts, the order between individual compositions (for the same n) is (list-)reversed co-lexicographic. [Joerg Arndt, Sep 02 2013] Dropping the "(list-)reversed" in the comment above gives A228525. The equivalent sequence for partitions is A026792. Row n has length A001792(n-1). Row sums give A001787, n >= 1. LINKS Peter Kagey, Table of n, a(n) for n = 1..10000 EXAMPLE Illustration of initial terms: ----------------------------------- n  j     Diagram     Composition j ----------------------------------- .         _ 1  1     |_|         1; .         _ _ 2  1     |_  |       2, 2  2     |_|_|       1, 1; .         _ _ _ 3  1     |_    |     3, 3  2     |_|_  |     1, 2, 3  3     |_  | |     2, 1, 3  4     |_|_|_|     1, 1, 1; .         _ _ _ _ 4  1     |_      |   4, 4  2     |_|_    |   1, 3, 4  3     |_  |   |   2, 2, 4  4     |_|_|_  |   1, 1, 2, 4  5     |_    | |   3, 1, 4  6     |_|_  | |   1, 2, 1, 4  7     |_  | | |   2, 1, 1, 4  8     |_|_|_|_|   1, 1, 1, 1; . Triangle begins: [1]; [2],[1,1]; [3],[1,2],[2,1],[1,1,1]; [4],[1,3],[2,2],[1,1,2],[3,1],[1,2,1],[2,1,1],[1,1,1,1]; [5],[1,4],[2,3],[1,1,3],[3,2],[1,2,2],[2,1,2],[1,1,1,2],[4,1],[1,3,1],[2,2,1],[1,1,2,1],[3,1,1],[1,2,1,1],[2,1,1,1],[1,1,1,1,1]; ... PROG (Haskell) a228351 n = a228351_list !! (n - 1) a228351_list = concatMap a228351_row [1..] a228351_row 0 = [] a228351_row n = a001511 n : a228351_row (n `div` 2^(a001511 n)) -- Peter Kagey, Jun 27 2016 CROSSREFS Cf. A001511, A006519, A011782, A026792, A065120, A066099, A228525, A228369. Sequence in context: A128221 A175488 A115758 * A124734 A037034 A229897 Adjacent sequences:  A228348 A228349 A228350 * A228352 A228353 A228354 KEYWORD nonn,tabf AUTHOR Omar E. Pol, Aug 30 2013 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 20 10:13 EDT 2019. Contains 324234 sequences. (Running on oeis4.)