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Search: id:A092472
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| A092472 |
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a(n)=sum(i+j+k=n,(2n)!/(i+j)!/(j+k)!/(k+i)!) 0<=i<=n, 0<=j<=n, 0<=k<=n. |
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+0
1
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| 1, 6, 54, 510, 4830, 45486, 425502, 3956238, 36594558, 337038702, 3093092574, 28302208974, 258331692606, 2353101799470, 21397006320030, 194281959853710, 1761880227283710, 15961196057303790, 144466419007648350
(list; graph; listen)
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OFFSET
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0,2
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PROGRAM
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(PARI) a(n)=sum(i=0, n, sum(j=0, n, sum(k=0, n, if(i+j+k-n, 0, (2*n)!/(i+j)!/(j+k)!/(k+i)!))))
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CROSSREFS
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Sequence in context: A125837 A065088 A092810 this_sequence A098658 A109576 A069726
Adjacent sequences: A092469 A092470 A092471 this_sequence A092473 A092474 A092475
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KEYWORD
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nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 25 2004
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