|
| |
|
|
A117079
|
|
a(1) = 1; a(n) = 2*a(n-1) + (number of digits in a(n-1)).
|
|
1
|
|
|
|
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;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
Harvey P. Dale, Table of n, a(n) for n = 1..1000
|
|
|
EXAMPLE
|
1*2+1=3
3*2+1=7
7*2+1=15
15*2+2=3
etc.
|
|
|
MATHEMATICA
|
a[1] = 1; a[n_] := a[n] = 2a[n - 1] + Floor[Log[10, a[n - 1]]] + 1 - Robert G. Wilson v, Apr 20 2006
RecurrenceTable[{a[1]==1, a[n]==2a[n-1]+IntegerLength[a[n-1]]}, a[n], {n, 40}] (* Harvey P. Dale, May 03 2011 *)
NestList[2#+IntegerLength[#]&, 1, 30] (* Harvey P. Dale, Oct 01 2012 *)
|
|
|
CROSSREFS
|
Sequence in context: A066175 A132978 A336976 * A026745 A139333 A099444
Adjacent sequences: A117076 A117077 A117078 * A117080 A117081 A117082
|
|
|
KEYWORD
|
easy,nonn,base
|
|
|
AUTHOR
|
Zededarian Zee (Zededarian(AT)Gmail.com), Apr 19 2006
|
|
|
EXTENSIONS
|
More terms from Stefan Steinerberger, Jonathan Vos Post, Robert G. Wilson v and James Greene (jmg482(AT)psu.edu), Apr 20 2006. Also from Atilla Bora (borabanana(AT)gmail.com), Apr 23 2006
|
|
|
STATUS
|
approved
|
| |
|
|
