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A062813
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Sum i*n^i, i = 0..n-1.
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7
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0, 2, 21, 228, 2930, 44790, 800667, 16434824, 381367044, 9876543210, 282458553905, 8842413667692, 300771807240918, 11046255305880158, 435659737878916215, 18364758544493064720, 824008854613343261192
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Largest Katadrome (number with digits in strict descending order) in base n.
The largest permutational number (A134640) of order n. These numbers are isomorphic with antidiagonal permutation matrices of order n. Where diagonal matrices are a[i,1+n-i]=1 {i=1,n} a[i<>1+n-i]=0 for smallest permutational numbers of order n see A023811 - Artur Jasinski (grafix(AT)csl.pl), Nov 07 2007
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
| a(n) = n^n - (n^n-n)/(n-1)^2 for n>1. - Dean Hickerson, Jun 26, 2001
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MATHEMATICA
| Table[Sum[i*n^i, {i, 0, -1 + n}], {n, 17}] (* Gerard *)
a = {0}; Do[c = {}; Do[AppendTo[c, n - k], {k, 0, n}]; AppendTo[a, FromDigits[c, n + 1]], {n, 1, 20}]; a (* Artur Jasinski, Nov 08 2007 *)
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PROG
| (PARI) a(n) = sum(i=0, n-1, i*n^i)
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CROSSREFS
| Cf. A134640, A134641, A134642, A134643, A134644, A023811, A062808.
Sequence in context: A058476 A099748 A023812 * A024231 A069717 A036679
Adjacent sequences: A062810 A062811 A062812 * A062814 A062815 A062816
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KEYWORD
| nonn,easy
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AUTHOR
| Olivier Gerard (olivier.gerard(AT)gmail.com), Jun 23 2001
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