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Search: id:A107862
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| A107862 |
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Triangle, read by rows, where T(n,k) = C(n*(n-1)/2-k*(k-1)/2+n-k, n-k). |
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+0
13
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| 1, 1, 1, 3, 2, 1, 20, 10, 3, 1, 210, 84, 21, 4, 1, 3003, 1001, 220, 36, 5, 1, 54264, 15504, 3060, 455, 55, 6, 1, 1184040, 296010, 53130, 7315, 816, 78, 7, 1, 30260340, 6724520, 1107568, 142506, 14950, 1330, 105, 8, 1, 886163135, 177232627, 26978328, 3262623
(list; table; graph; listen)
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OFFSET
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0,4
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COMMENT
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Remarkably, the following matrix products are all equal to A107876: A107862^-1*A107867 = A107867^-1*A107870 = A107870^-1*A107873.
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EXAMPLE
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Triangle begins:
1;
1,1;
3,2,1;
20,10,3,1;
210,84,21,4,1;
3003,1001,220,36,5,1;
54264,15504,3060,455,55,6,1;
1184040,296010,53130,7315,816,78,7,1; ...
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PROGRAM
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(PARI) T(n, k)=binomial(n*(n-1)/2-k*(k-1)/2+n-k, n-k)
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CROSSREFS
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Cf. A014068 (column 0), A107864 (column 1), A107863 (column 2), A107865, A107867, A107870, A107876.
Adjacent sequences: A107859 A107860 A107861 this_sequence A107863 A107864 A107865
Sequence in context: A129377 A136733 A117269 this_sequence A117265 A107727 A087041
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KEYWORD
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nonn,tabl
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Jun 04 2005
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