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A117079
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a(1) = 1; a(n) = 2*a(n-1) + (number of digits in a(n-1)).
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0
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1, 3, 7, 15, 32, 66, 134, 271, 545, 1093, 2190, 4384, 8772, 17548, 35101, 70207, 140419, 280844, 561694, 1123394, 2246795, 4493597, 8987201, 17974409, 35948826, 71897660, 143795328, 287590665, 575181339, 1150362687, 2300725384
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| 1*2+1=3
3*2+1=7
7*2+1=15
15*2+2=3
etc.
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MATHEMATICA
| a[1] = 1; a[n_] := a[n] = 2a[n - 1] + Floor[Log[10, a[n - 1]]] + 1 - Robert G. Wilson v (rgwv(at)rgwv.com), Apr 20 2006
RecurrenceTable[{a[1]==1, a[n]==2a[n-1]+IntegerLength[a[n-1]]}, a[n], {n, 40}] (* From Harvey P. Dale, May 03 2011 *)
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CROSSREFS
| Sequence in context: A147250 A066175 A132978 * A026745 A139333 A099444
Adjacent sequences: A117076 A117077 A117078 * A117080 A117081 A117082
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KEYWORD
| easy,nonn,base
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AUTHOR
| Zededarian Zee (Zededarian(AT)Gmail.com), Apr 19 2006
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EXTENSIONS
| More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jonathan Vos Post (jvospost3(AT)gmail.com), Robert G. Wilson v (rgwv(at)rgwv.com) and James Greene (jmg482(AT)psu.edu), Apr 20 2006. Also from Atilla Bora (borabanana(AT)gmail.com), Apr 23 2006
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