[seqfan] Re: A019575 challenge

Ron Hardin rhhardin at att.net
Mon Aug 23 16:18:18 CEST 2010


T(n,k)=Number of arrangements of n indistinguishable balls in n boxes with the 
maximum number of balls in any box equal to k


T(n,2)=sum{j=1..n} binomial(n,j)*binomial(n-j,j)
(via A097861)

2 2
3 6
4 18
5 50
6 140
7 392
8 1106
9 3138
10 8952
11 25652
12 73788
13 212940
14 616226
15 1787606
16 5196626
17 15134930
18 44152808
19 128996852
20 377379368
21 1105350728
22 3241135526
23 9513228122
24 27948336380
25 82176836300
26 241813226150
27 712070156202
28 2098240353906
29 6186675630818
30 18252025766940
31 53876592856680
32 159114492071762
33 470139239360786
34 1389754816243448
35 4109922421017092
36 12159131877715992
37 35986168879543608
38 106542797484006470
39 315544068167601786
40 934837217271732456
41 2770417140954208376
42 8212609533895771130
43 24352194654450483758
44 72228808291130603702
45 214285636273290835238
46 635888739568958641448
47 1887427033736750828036
48 5603455843421135356412
49 16639279789182494873660
50 49419934162239477797702
51 146809908211050225267002
52 436205201395400255875958
53 1296299845800770981294870
54 3852976120787983994126456
55 11454090403374820987810052
56 34056162405439687297817522
57 101274272624239554221148578
58 301209398674443711437222120
59 895986831890298248688726116

 rhhardin at mindspring.com
rhhardin at att.net (either)





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