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What is the number before 4181 in the Fibonacci sequence. Explain how you could work this out without knowing all the numbers in the sequence
Hmm, I'm thinking this has something to do with PHI...
"There is not a difference between an in-law and an outlaw, except maybe that an outlaw is wanted"
Nisi Quam Primum, Nequequam
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One funny way is to add a zero to 4181 to make 41810.
Now start with this series: 0 10 10 20 30 50 80 130 210 340 550 890
1440
2330
3770
This number is overloading digits above 9 in the base-10 system:
5(10)(10)0
8(17)(17)0
13(27)(27)0
21(44)(44)0
34(71)(71)0
Calculate this:
34000 + 7100 + 710 =
41100 + 710 =
41810
Yep!! We did it without looking at
all of the numbers!!
Answer = 2100 + 440 + 44 = 2584
Also if you multiply 4181 by 0.618 you get just a tad under 2584,
and 0.618 and 1.618 are nearly reciprocals (golden ratio)
(√5 + 1)/2
Last edited by John E. Franklin (2008-02-15 18:31:54)
igloo myrtilles fourmis
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