OFFSET
1,1
COMMENTS
The minimum, average and maximum of a(n)/10^n are approximately equal to 1.38197968245, 1.87028385088 & 2.38195747810, respectively, for the first 30000 terms.
Observation: the minimum seems to be just over (5-sqrt(5))/2, the maximum seems to be just shy of (7-sqrt(5))/2; the average is not (6-sqrt(5))/2 but seems to be closer to (5-sqrt(11))/9. - Robert G. Wilson v, May 26 2007
Observation: There are approximately twice as many odd terms as even ones.
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..100
C. Valente, PlanetMath.org, List of Fibonacci Numbers
Wikipedia, Fibonacci Numbers.
FORMULA
EXAMPLE
If n=1 then the sum of the Fibonacci numbers 1+1+2+3+5+8 = 20 which is the first term in the sequence.
If n=2 then the sum of the Fibonacci numbers 13+21+34+55+89 = 212 which is the second term in the sequence.
MATHEMATICA
f[n_] := Plus @@ Select[ Fibonacci /@ Range[ Floor[(n - 1)*Log[ GoldenRatio, 10] + 1], Floor[ n*Log[ GoldenRatio, 10] + 3]], Floor@ Log[10, # ] + 1 == n &]; Array[f, 18] (* Robert G. Wilson v, May 26 2007 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Apr 11 2007
EXTENSIONS
More terms from Robert G. Wilson v, May 26 2007
STATUS
approved