login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A254243 Number of ways to partition the multiset consisting of 3 copies each of 1, 2, ..., n into n sets of size 3. 5

%I #40 Apr 18 2020 22:21:29

%S 1,1,2,10,93,1417,32152,1016489,42737945,2307295021,155607773014,

%T 12823004639504,1267907392540573,148160916629902965,

%U 20199662575448858212,3177820001990224608763,571395567211112572679633,116448309072281063992943561,26700057600529091443246943530

%N Number of ways to partition the multiset consisting of 3 copies each of 1, 2, ..., n into n sets of size 3.

%H Andrew Howroyd, <a href="/A254243/b254243.txt">Table of n, a(n) for n = 0..100</a>

%H P. A. MacMahon, <a href="http://plms.oxfordjournals.org/content/s2-17/1/25.extract">Combinations derived from m identical sets of n different letters and their connexion with general magic squares</a>, Proc. London Math. Soc., 17 (1917), 25-41. See page 40 (but there is a typo).

%H StackExchange, <a href="http://math.stackexchange.com/questions/1126151/number-of-partitioning-a-deck-with-m-cards-in-n-types-into-n-element-sets/1127188#1127188">Number of Partitioning a deck with m cards in n types into n-element sets</a>, January 2015.

%e a(1) = 1: 111.

%e a(2) = 2: 111|222 and 112|122.

%e a(3) = 10: 111|222|333, 111|223|233, 112|122|333, 112|123|233, 112|133|223, 113|122|233, 113|123|223, 113|133|222, 122|123|133, and 123|123|123.

%Y Cf. A002135 (2 instead of 3), A254233 (n copies each of 1, 2, and 3).

%Y Column k=3 of A257463.

%K nonn

%O 0,3

%A _Tatsuru Murai_, Jan 27 2015

%E Name and example edited by _Danny Rorabaugh_, Apr 22 2015

%E a(6)-a(10) from _Alois P. Heinz_, Apr 22 2015

%E Terms a(11) and beyond from _Andrew Howroyd_, Apr 18 2020

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 11:21 EDT 2024. Contains 371936 sequences. (Running on oeis4.)