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A089907
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Sum of digits of numbers between 0 and (6/9)*(10^n-1).
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6
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0, 21, 483, 7785, 107787, 1377789, 16777791, 197777793, 2277777795, 25777777797, 287777777799, 3177777777801, 34777777777803, 377777777777805, 4077777777777807, 43777777777777809, 467777777777777811
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| From a suggestion of Yalcin Aktar (aktaryalcin(AT)msn.com)
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FORMULA
| a(n)=s(6, n-1) where s(a, k)=a*(k+1)+a^2*sum(i=0, k, i*10^(k-i))+sum(i=0, k, 5*a*(9*(k-i)+a- 1)*10^(k-i-1))
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CROSSREFS
| Cf. A089903, A089904, A089905, A087330, A089906, A089908, A089909, A034967.
Sequence in context: A158603 A025603 A006298 * A015695 A006299 A065921
Adjacent sequences: A089904 A089905 A089906 * A089908 A089909 A089910
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KEYWORD
| nonn,base
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Nov 14 2003
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