

A103921


Table of number of distinct parts of partitions of n in AbramowitzStegun order.


9



0, 1, 1, 1, 1, 2, 1, 1, 2, 1, 2, 1, 1, 2, 2, 2, 2, 2, 1, 1, 2, 2, 1, 2, 3, 1, 2, 2, 2, 1, 1, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 1, 1, 2, 2, 2, 1, 2, 3, 3, 2, 2, 2, 3, 2, 3, 1, 2, 3, 2, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 3, 3, 2, 2, 3, 1, 2, 3, 3, 3, 3, 2, 2, 3, 2, 3, 2, 2, 3, 2, 2, 2, 2, 1, 1, 2, 2, 2, 2, 1, 2, 3
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OFFSET

0,6


COMMENTS

The row length sequence of this table is p(n)=A000041(n) (number of partitions).
In order to count distinct parts of a partition consider the partition as a set instead of a multiset. E.g., n=6: read [1,1,1,3] as {1,3} and count the elements, here 2.
Rows are the same as the rows of A115623, but in reverse order.
From Wolfdieter Lang, Mar 17 2011: (Start)
The number of 1s in row number n, n >= 1, is tau(n)=A000005(n), the number of divisors of n.
For the proof read off the divisors d(n,j), j=1..tau(n), from row number n of table A027750, and translate them to the tau(n) partitions d(n,1)^(n/d(n,1)), d(n,2)^(n/d(n,2)),..., d(n,tau(n))^(n/d(n,tau(n))).
See a comment by Giovanni Resta under A000005. (End)


LINKS

Table of n, a(n) for n=0..104.
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, pp. 8312.
Wolfdieter Lang, First 10 rows.


FORMULA

a(n, m) = number of distinct parts of the mth partition of n in AbramowitzStegun order; n >= 0, m = 1..p(n) = A000041(n).


EXAMPLE

Triangle starts:
0,
1,
1, 1,
1, 2, 1,
1, 2, 1, 2, 1,
1, 2, 2, 2, 2, 2, 1,
1, 2, 2, 1, 2, 3, 1, 2, 2, 2, 1,
1, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 1,
1, 2, 2, 2, 1, 2, 3, 3, 2, 2, 2, 3, 2, 3, 1, 2, 3, 2, 2, 2, 2, 1,
1, 2, 2, 2, 2, ...
a(5,4)=2 from the fourth partition of 5 in the mentioned order, i.e., (1^2,3), which has two distinct parts, namely 1 and 3.


CROSSREFS

Cf. A036036, A000041, A115623, A115621, row sums A000070.
Sequence in context: A309414 A007421 A239228 * A115623 A279044 A134265
Adjacent sequences: A103918 A103919 A103920 * A103922 A103923 A103924


KEYWORD

nonn,tabf


AUTHOR

Wolfdieter Lang, Mar 24 2005


EXTENSIONS

Edited by Franklin T. AdamsWatters, May 29 2006


STATUS

approved



