Wolfram Language™

Find a Sequence in the Digits of π

The new functions SequenceCases, SequencePosition, and SequenceCount offer new functionality to extract sequences using pattern matching.

Find the occurrence of the first release date of Mathematica in the digits of .

In[1]:=

EntityValue[ Entity["ProgrammingLanguage", "WolframLanguage"], "DateIntroduced"]

Out[1]=

Change this date to a format suited to the search.

In[2]:=

EntityValue[ Entity["ProgrammingLanguage", "WolframLanguage"], "DateIntroduced"]; date = Characters[DateString[%, {"Month", "Day", "YearShort"}]]

Out[2]=

Generate the first three million digits of .

In[3]:=

pi = Characters[ToString@N[Pi, 3000000]];

SequencePosition gives the positions at which the formatted date starts and ends.

In[4]:=

pos = SequencePosition[pi, date]

Out[4]=

It appears only once in the first three million digits of . This occurrence can be represented in a simple way using a Grid object.

In[5]:=

chars = Join[ Take[pi, 21], Characters["..."], Take[pi, First@pos - {14, 6}], Style[#, Orange] & /@ Take[pi, First@pos], Take[pi, First@pos + {6, 4}] ];

In[6]:=

Grid[Partition[chars, 8]]

Out[6]=

Try other dates and find your day here!