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A325854 Number of strict integer partitions of n such that every pair of distinct parts has a different quotient. 11

%I #9 Feb 05 2022 02:31:35

%S 1,1,1,2,2,3,4,4,6,8,9,12,13,16,20,23,30,33,41,47,52,61,75,90,98,116,

%T 132,151,173,206,226,263,297,337,387,427,488,555,623,697,782,886,984,

%U 1108,1240,1374,1545,1726,1910,2120,2358,2614,2903,3218,3567,3933

%N Number of strict integer partitions of n such that every pair of distinct parts has a different quotient.

%C Also the number of strict integer partitions of n such that every pair of (not necessarily distinct) parts has a different product.

%H Fausto A. C. Cariboni, <a href="/A325854/b325854.txt">Table of n, a(n) for n = 0..300</a>

%e The a(1) = 1 through a(10) = 9 partitions (A = 10):

%e (1) (2) (3) (4) (5) (6) (7) (8) (9) (A)

%e (21) (31) (32) (42) (43) (53) (54) (64)

%e (41) (51) (52) (62) (63) (73)

%e (321) (61) (71) (72) (82)

%e (431) (81) (91)

%e (521) (432) (532)

%e (531) (541)

%e (621) (631)

%e (721)

%e The two strict partitions of 13 such that not every pair of distinct parts has a different quotient are (9,3,1) and (6,4,2,1).

%t Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&UnsameQ@@Divide@@@Subsets[Union[#],{2}]&]],{n,0,30}]

%Y The subset case is A325860.

%Y The maximal case is A325861.

%Y The integer partition case is A325853.

%Y The strict integer partition case is A325854.

%Y Heinz numbers of the counterexamples are given by A325994.

%Y Cf. A108917, A143823, A196724, A275972, A325768, A325855, A325858, A325868, A325869, A325876, A325877.

%K nonn

%O 0,4

%A _Gus Wiseman_, May 31 2019

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Last modified April 23 06:04 EDT 2024. Contains 371906 sequences. (Running on oeis4.)