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Search: id:A057884
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| A057884 |
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A square array based on tetrahedral numbers (A000292) with each term being the sum of 2 consecutive terms in the previous row. |
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+0
5
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| 1, 0, 1, 4, 1, 1, 0, 4, 2, 1, 10, 4, 5, 3, 1, 0, 10, 8, 7, 4, 1, 20, 10, 14, 13, 10, 5, 1, 0, 20, 20, 22, 20, 14, 6, 1, 35, 20, 30, 34, 35, 30, 19, 7, 1, 0, 35, 40, 50, 56, 55, 44, 25, 8, 1, 56, 35, 55, 70, 84, 91, 85, 63, 32, 9, 1, 0, 56, 70, 95, 120, 140, 146, 129, 88, 40, 10, 1
(list; table; graph; listen)
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OFFSET
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0,4
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FORMULA
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T(n, k)=T(n-1, k-1)+T(n, k-1) with T(0, k)=1, T(4, 1)=4, T(0, 2n)=T(4, n), and T(0, 2n+1)=0. Coefficient of x^n in expansion of (1+x)^k/(1-x^2)^4.
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EXAMPLE
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Rows are (1,0,4,0,10,0,20,...), (1,1,4,4,10,10,20,...), (1,2,5,8,14,20,30,...), (1,3,7,13,22,34,50,...), (1,4,10,20,35,56,84,...) etc.
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CROSSREFS
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Rows are A000292 with zeros, A058187 (A000292 with terms duplicated), A006918, A002623, A000292, A000330, A005900, A001845, A008412.
Sequence in context: A085639 A135302 A128760 this_sequence A016684 A122777 A103524
Adjacent sequences: A057881 A057882 A057883 this_sequence A057885 A057886 A057887
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KEYWORD
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easy,nonn,tabl
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AUTHOR
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Henry.Bottomley (se16(AT)btinternet.com), Nov 20 2000
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