A brief overview of the first 10 million characters of Pi
Introduction
Recently I came across this video:
In it, the British guys talk about how they printed the Pi number up to a million mark on a paper tape, and then rolled it out on the runway. It turned out the tape length of 1.69 km. For orientation in this set of digits every 10 characters is the corresponding label.
During their event, the authors tell about interesting places of Pi. So, on the 762nd symbol begins the so-called. Feynman point . The nearest sequence consisting of the same numbers, longer than this will be only 710000 digits.
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One of the commentators shared a link and added "Learn." This story is devoted to such a superficial study of the first 10 million characters of Pi.
Overview
The first thought is, of course, to count how many times units, twos, etc. meet here. Intuition suggests that the number of meetings with each digit should be about a million. Slightly less lazy readers can apply mathematical statistics techniques when processing results, but I will confine myself to the following table.
Numeral
Number of meetings
0
999440
one
999333
2
1000306
3
999965
four
1001093
five
1000466
6
999337
7
1000207
eight
999814
9
10,00040
Here, exactly in half of the cases, the number of meetings is greater than expected. Expected.
Next, let's see how often in our number there are pairs, twos, triples, etc. same numbers. The results are shown in a similar table. Eight in a row any identical numbers are not found in the considered number of characters Pi.
Numeral
Two in a row
Three in a row
Four in a row
Five in a row
Six in a row
Seven in a row
0
98638
9669
872
87
6
one
one
98689
9629
976
101
ten
one
2
98969
9775
948
84
9
0
3
99552
9831
934
87
7
one
four
98934
9583
891
87
eight
0
five
99483
9953
1006
97
eleven
2
6
98867
9599
940
96
9
one
7
99194
9780
1004
112
14
2
eight
98761
9641
911
92
sixteen
2
9
99112
9977
1005
103
17
four
From the interesting here: continuous sequences of nines are more common. And 999999 appears more often 000000 almost three times.
And finally, a brief look at what other sequences are found in Pi. So, once there is a series of 1234567 , which is the longest sequence in a row arranged in ascending order of numbers. If we look for rows of digits arranged in descending order, then the longest of them is 876543210 and it occurs once.
Instead of conclusion
Next, I decided to see how the number Pi intersects with other known constants. So, the first 6 digits of the number e (e = 2.71828) are found 7 times, like the first 6 digits of Pi himself. It would be interesting to look for intersections of known constants, but the research method applied here (Ctrl + F at pi.karmona.com ) is not suitable for this. One of the databases of known constants is oeis.org .