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Search: id:A062808
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| A062808 |
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Sum n^i*(n - i), i = 1..n. |
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+0
3
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| 0, 2, 15, 108, 970, 11190, 160125, 2739128, 54480996, 1234567890, 31384283755, 884241366756, 27342891567342, 920521275489998, 33512287529147385, 1311768467463790320, 54933923640889550728, 2450641333409472928554
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Permutational numbers A134640 isomorphic with permutation matrix generators of cyclic groups, n-th root of unity matrices. - Artur Jasinski (grafix(AT)csl.pl), Nov 07 2007
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FORMULA
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a(n) = (n^(n+1)-n^3+n^2-n)/(n-1)^2 for n>1. - Dean Hickerson, Jun 26, 2001
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MATHEMATICA
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Sum[n^i*(n - i), {i, 1, n}]
a = {}; b = {}; c = {}; Do[AppendTo[b, n]; c = b; AppendTo[c, 0]; AppendTo[a, FromDigits[c, n + 1]], {n, 1, 20}]; a (* Artur Jasinski *) - Artur Jasinski (grafix(AT)csl.pl), Nov 07 2007
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CROSSREFS
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Cf. A134640, A134641, A134642, A134643, A134644, A023811.
Sequence in context: A037740 A037635 A154635 this_sequence A162773 A140637 A022026
Adjacent sequences: A062805 A062806 A062807 this_sequence A062809 A062810 A062811
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KEYWORD
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nonn,easy
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AUTHOR
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Olivier Gerard (olivier.gerard(AT)gmail.com), Jun 23 2001
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