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A240750 Table where row n contains all compositions of n into an even number of parts. 1
1, 1, 2, 1, 1, 2, 3, 1, 2, 2, 1, 3, 1, 1, 1, 1, 4, 1, 3, 2, 2, 3, 2, 1, 1, 1, 1, 4, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 5, 1, 4, 2, 3, 3, 3, 1, 1, 1, 2, 4, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2, 1, 5, 1, 3, 1, 1, 1, 2, 2, 1, 1, 2, 1, 2, 1, 1, 3, 1, 1, 1, 2, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

COMMENTS

Can also be regarded as a table where row n is the n-th composition into an even number of parts, sorted by sum of composition and then reverse lexicographically.

LINKS

Table of n, a(n) for n=2..97.

EXAMPLE

The table starts:

{}

(none)

11

21,12

31,22,13,1111

41,32,23,2111,14,1211,1121,1112

51,42,33,3111,24,2211,2121,2112,15,1311,1221,1212,1131,1122,1113,111111

PROG

(PARI) evil(n) = local(r=0, m=n); while(m>0, if(m%2==1, r=1-r); m\=2); n*2+r

A066099row(n) = {local(v=vector(n), j=0, k=0);

   while(n>0, k++; if(n%2==1, v[j++]=k; k=0); n\=2);

   vector(j, i, v[j-i+1])}

arow(n)=A066099row(evil(n))

CROSSREFS

Cf. A066099, A240837, A001969, A034008 (compositions in rows), A087447 (parts in rows for n>2).

Sequence in context: A105810 A063726 A290267 * A181118 A179009 A112757

Adjacent sequences:  A240747 A240748 A240749 * A240751 A240752 A240753

KEYWORD

nonn,tabf

AUTHOR

Franklin T. Adams-Watters, Apr 12 2014

STATUS

approved

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Last modified March 20 15:43 EDT 2019. Contains 321345 sequences. (Running on oeis4.)