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!)
A362609 Number of integer partitions of n with more than one part of least multiplicity. 33

%I #7 May 02 2023 16:08:00

%S 0,0,0,1,1,2,4,5,9,14,19,26,42,51,74,103,136,174,246,303,411,523,674,

%T 844,1114,1364,1748,2174,2738,3354,4247,5139,6413,7813,9613,11630,

%U 14328,17169,20958,25180,30497,36401,44025,52285,62834,74626,89111,105374,125662

%N Number of integer partitions of n with more than one part of least multiplicity.

%C These are partitions where no part appears fewer times than all of the others.

%e The partition (4,2,2,1) has least multiplicity 1, and two parts of multiplicity 1 (namely 1 and 4), so is counted under a(9).

%e The a(3) = 1 through a(9) = 14 partitions:

%e (21) (31) (32) (42) (43) (53) (54)

%e (41) (51) (52) (62) (63)

%e (321) (61) (71) (72)

%e (2211) (421) (431) (81)

%e (3211) (521) (432)

%e (3221) (531)

%e (3311) (621)

%e (4211) (3321)

%e (32111) (4221)

%e (4311)

%e (5211)

%e (42111)

%e (222111)

%e (321111)

%t Table[Length[Select[IntegerPartitions[n],Count[Length/@Split[#],Min@@Length/@Split[#]]>1&]],{n,0,30}]

%Y For parts instead of multiplicities we have A117989, ranks A283050.

%Y For median instead of co-mode we have A238479, complement A238478.

%Y These partitions have ranks A362606.

%Y For mode instead of co-mode we have A362607, ranks A362605.

%Y For mode complement instead of co-mode we have A362608, ranks A356862.

%Y The complement is counted by A362610, ranks A359178.

%Y A000041 counts integer partitions.

%Y A275870 counts collapsible partitions.

%Y A359893 counts partitions by median.

%Y A362611 counts modes in prime factorization, co-modes A362613.

%Y A362614 counts partitions by number of modes, co-modes A362615.

%Y Cf. A002865, A008284, A053263, A098859, A304442, A353864, A360071, A362612.

%K nonn

%O 0,6

%A _Gus Wiseman_, Apr 30 2023

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 August 14 07:30 EDT 2024. Contains 375146 sequences. (Running on oeis4.)