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PROJECT EULER · #0419

Look and Say Sequence

Statement only · UnsolvedOriginal problem ↗

The look and say sequence goes 1, 11, 21, 1211, 111221, 312211, 13112221, 1113213211, ...
The sequence starts with 1 and all other members are obtained by describing the previous member in terms of consecutive digits.
It helps to do this out loud:
1 is 'one one' → 11
11 is 'two ones' → 21
21 is 'one two and one one' → 1211
1211 is 'one one, one two and two ones' → 111221
111221 is 'three ones, two twos and one one' → 312211
...

Define A(n), B(n) and C(n) as the number of ones, twos and threes in the n'th element of the sequence respectively.
One can verify that A(40)=31254, B(40)=20259 and C(40)=11625.

Find A(n), B(n) and C(n) for n=1012.
Give your answer modulo 230 and separate your values for A, B and C by a comma.
E.g. for n=40 the answer would be 31254,20259,11625

Write-up coming later

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