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Search: id:A089909
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| A089909 |
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Sum of digits of numbers between 0 and (8/9)*(10^n-1). |
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+0
6
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| 0, 36, 748, 11460, 154572, 1945684, 23456796, 274567908, 3145679020, 35456790132, 394567901244, 4345679012356, 47456790123468, 514567901234580, 5545679012345692, 59456790123456804, 634567901234567916
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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From a suggestion of Yalcin Aktar (aktaryalcin(AT)msn.com)
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FORMULA
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a(n)=s(8, 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
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Cf. A089903, A089904, A089905, A087330, A089906, A089907, A089908, A034967.
Sequence in context: A064541 A058001 A004329 this_sequence A049434 A036084 A004338
Adjacent sequences: A089906 A089907 A089908 this_sequence A089910 A089911 A089912
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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), Nov 14 2003
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