cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A360691 Number of integer partitions of n with non-integer median of 0-prepended first differences.

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%I A360691 #5 Feb 24 2023 21:46:41
%S A360691 0,1,0,1,2,4,3,4,5,10,10,15,22,26,34,42,57,63,85,105,121,149,202,230,
%T A360691 305,355,459,544,687,778,991,1130,1396,1598,1947,2258,2761,3143,3820,
%U A360691 4412,5330,6104,7404,8499,10105,11694,13922,15917,18904,21646,25462,29213
%N A360691 Number of integer partitions of n with non-integer median of 0-prepended first differences.
%C A360691 All of these partitions have even length.
%C A360691 The median of a multiset is either the middle part (for odd length), or the average of the two middle parts (for even length).
%e A360691 The a(1) = 0 through a(10) = 10 partitions:
%e A360691   .  (11)  .  (31)  (32)    (33)    (52)    (53)    (54)      (55)
%e A360691                     (2111)  (51)    (2221)  (71)    (72)      (73)
%e A360691                             (2211)  (4111)  (3311)  (3222)    (91)
%e A360691                             (3111)          (5111)  (6111)    (3322)
%e A360691                                                     (321111)  (3331)
%e A360691                                                               (4411)
%e A360691                                                               (5311)
%e A360691                                                               (7111)
%e A360691                                                               (322111)
%e A360691                                                               (421111)
%t A360691 Table[Length[Select[IntegerPartitions[n], !IntegerQ[Median[Differences[Prepend[Reverse[#],0]]]]&]],{n,30}]
%Y A360691 For median 0 we have A360254, ranks A360558.
%Y A360691 These partitions have ranks A360557, complement A360556.
%Y A360691 The complement is counted by A360688.
%Y A360691 A000041 counts integer partitions, strict A000009.
%Y A360691 A008284 counts partitions by number of parts.
%Y A360691 A325347 counts partitions with integer median, complement A307683.
%Y A360691 A359893 and A359901 count partitions by median, odd-length A359902.
%Y A360691 Cf. A000975, A027193, A237363, A240219, A359907, A359908, A360455, A360555.
%K A360691 nonn
%O A360691 1,5
%A A360691 _Gus Wiseman_, Feb 22 2023