ROSECODE 435
Harmonic variations
It is well known that the Harmonic serie is divergent.
A more surprising result is that if we remove all numbers containing at least one digit 9 the corresponding serie is convergent.
What is
where is the set of all numbers with exactly one digit 2 and one digit 4 in their base-10 representation
Answer format: Give the result with the first 20 digits after the decimal point.
[My timing : < 1 sec]
A more surprising result is that if we remove all numbers containing at least one digit 9 the corresponding serie is convergent.
What is
where
Answer format: Give the result with the first 20 digits after the decimal point.
[My timing : < 1 sec]