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A124921 Distributes the number of permutations in the alternating group; cf. A060351 1
1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 3, 1, 1, 3, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,11

COMMENTS

The symmetric group distribution of permutation descents is summarized in Table A008292; for example 1 57 302 302 57 1 sums the following A060351 values:

1.......5.......10.......10.......5.......1

.......14.......35.......35.......14.......

.......19.......26.......40.......19.......

.......14.......40.......19.......14.......

........5.......61.......26.......5.......

................26.......61..............

................19.......40..............

................40.......26..............

................35.......35..............

................10.......10..............

LINKS

Table of n, a(n) for n=0..15.

EXAMPLE

The distribution is based on the frequency of descents; for example, when permuting four symbols the 12 patterns are ddd ddu dud udu dud duu udd udu dud udu uud and uuu yielding the frequency distribution 1 1 3 1 1 3 1 1

1;

1;

1, 0;

1, 1, 1, 0;

1, 1, 3, 1, 1, 3, 1, 1;

CROSSREFS

Cf. A001710 (row sums), A008292, A060351, A011782 (row lengths).

Sequence in context: A218332 A322506 A103496 * A267863 A262681 A076498

Adjacent sequences:  A124918 A124919 A124920 * A124922 A124923 A124924

KEYWORD

more,tabf,nonn,uned

AUTHOR

Alford Arnold, Nov 16 2006

STATUS

approved

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Last modified June 19 13:11 EDT 2019. Contains 324222 sequences. (Running on oeis4.)