The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A125106 Enumeration of partitions by binary representation: each 1 is a part; the part size is 1 more than the number of 0's in the rest of the number. 18
 1, 2, 1, 1, 3, 2, 1, 2, 2, 1, 1, 1, 4, 3, 1, 3, 2, 2, 1, 1, 3, 3, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 5, 4, 1, 4, 2, 3, 1, 1, 4, 3, 3, 2, 1, 3, 2, 2, 2, 1, 1, 1, 4, 4, 3, 3, 1, 3, 3, 2, 2, 2, 1, 1, 3, 3, 3, 2, 2, 2, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Another way to describe this: starting with the binary representation and a counter set at one, count the 0's from right to left. Write a term equal to the counter for each "1" encountered. A101211 is a similar sequence, with A005811 elements per row which maps natural numbers to compositions (ordered partitions). There are two ways to consider this as a table: taking each partition as a row, or taking the partitions generated by 2^(n-1) through 2^n-1 as a row. Taking the n-th row as multiple partitions, it consists of those partitions with the first hook size (largest part plus number of parts minus 1) equal to n. The number of integers in this n-th row is A001792(n-1), and the row sum is A049611. Taking each partition as a separate row, the row lengths are A000120, and the row sums are A161511. LINKS Alois P. Heinz, Rows n = 1..12, flattened FORMULA Partition 2n is partition n with every part size increased by 1; partition 2n+1 is partition n with an additional part of size 1. EXAMPLE Row 4: 1000  1001 [3,1] 1010 [3,2] 1011 [2,1,1] 1100 [3,3] 1101 [2,2,1] 1110 [2,2,2] 1111 [1,1,1,1] MAPLE b:= proc(n) local c, l, m; l:=[][]; m:= n; c:=1;       while m>0 do if irem(m, 2, 'm')=0 then c:= c+1          else l:= c, l fi       od; l     end: T:= n-> seq(b(i), i=2^(n-1)..2^n-1): seq(T(n), n=1..7);  # Alois P. Heinz, Sep 25 2015 MATHEMATICA f[k_] := (bits = IntegerDigits[k, 2]; zerosCount = Reverse[ Accumulate[ 1-Reverse[bits] ] ] + 1; Select[ Transpose[ {bits, zerosCount} ], First[#] == 1 & ][[All, 2]]); row[n_] := Table[ f[k], {k, 2^(n-1), 2^n-1}]; Flatten[ Table[ row[n], {n, 1, 5}]] (* Jean-François Alcover, Jan 24 2012 *) CROSSREFS Cf. A000041, A005811, A037016, A101211, A001792, A049611, A126411. Each partition as row: A000120 (row widths), A161511 (row sums), A243499 (row products). Cf. A005940. - Franklin T. Adams-Watters, Mar 06 2010 Sequence in context: A272121 A273135 A165162 * A229874 A330439 A243611 Adjacent sequences:  A125103 A125104 A125105 * A125107 A125108 A125109 KEYWORD tabf,nice,nonn AUTHOR Alford Arnold, Dec 10 2006 EXTENSIONS Edited by Franklin T. Adams-Watters, Jun 11 2009 STATUS approved

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

Last modified September 26 20:44 EDT 2022. Contains 357048 sequences. (Running on oeis4.)