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Search: id:A131765
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| A131765 |
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Series reversion of x(1-5x)/(1-x) . |
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+0
3
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| 1, 4, 36, 404, 5076, 68324, 963396, 14046964, 210062196, 3204118724, 49656709476, 779690085204, 12376867734036, 198301332087204, 3202580085625476, 52080967814444724, 852103170531254196, 14016301507253656964
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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The Hankel transform of this sequence is 20^C(n+1,2) .
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FORMULA
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a(n) = Sum_{k, 0<=k<=n}A086810(n,k)*4^k .
a(n)=sum{k=0..n, C(n+k,2k)*A000108(k)*(-1)^(n-k)*5^k}; a(n)=sum{k=0..n, C(n+k,2k)*A000108(k)*(4^(k+1)+(-1)^k)/5}. [From Paul Barry (pbarry(AT)wit.ie), Sep 08 2009]
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CROSSREFS
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Sequence in context: A138736 A019999 A002894 this_sequence A132864 A052700 A167540
Adjacent sequences: A131762 A131763 A131764 this_sequence A131766 A131767 A131768
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KEYWORD
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nonn
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AUTHOR
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Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 29 2007
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EXTENSIONS
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Extra terms added. Paul Barry (pbarry(AT)wit.ie), Sep 08 2009
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