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A131293
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Concatenate a(n-2) and a(n-1) to get a(n); start with a(0)=0, a(1)=1, delete the leading zero. Also Fib(n)-number of '1's.
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2
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0, 1, 1, 11, 111, 11111, 11111111, 1111111111111, 111111111111111111111, 1111111111111111111111111111111111, 1111111111111111111111111111111111111111111111111111111
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| Interpreted as base-2 numbers the result is A063896.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..18
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FORMULA
| a(n)=a(n-2)*10^ceiling(log_10(a(n-1)))+a(n-1) for n>1.
a(n)=(10^Fib(n)-1)/9 where Fib(n)=A000045(n).
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EXAMPLE
| a(3)=11, a(4)=111, so a(5)=a(4)a(3)=11111.
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MATHEMATICA
| Join[{0}, FromDigits/@(PadLeft[{}, #, 1]&/@Fibonacci[Range[10]])] (* From Harvey P. Dale, Aug 28 2011 *)
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PROG
| (MAGMA) [(10^Fibonacci(n)-1)/9: n in [0..10]]; // Vincenzo Librandi, Aug 29 2011
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CROSSREFS
| Cf. A000045, A061107.
Sequence in context: A015468 A037842 * A108047 A144784 A030175 A058949
Adjacent sequences: A131290 A131291 A131292 * A131294 A131295 A131296
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KEYWORD
| nonn
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AUTHOR
| Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Jun 26 2007
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