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A369411
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Irregular triangle read by rows: row n lists the number of symbols of a "normal" proof (see comments) for each of the distinct derivable strings (theorems) in the MIU formal system that are n characters long.
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5
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2, 13, 13, 5, 94, 94, 47, 94, 47, 47, 75, 75, 31, 75, 31, 31, 75, 31, 31, 31, 10, 120, 120, 165, 120, 165, 165, 120, 165, 165, 165, 90, 120, 165, 165, 165, 90, 165, 90, 90, 90, 43, 91, 91, 139, 91, 139, 139, 91, 139, 139, 139, 70, 91, 139, 139, 139, 70, 139, 70
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OFFSET
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2,1
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COMMENTS
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See A368946 for the description of the MIU formal system, A369173 for the triangle of the corresponding strings (theorems) and A369409 for the definition of "normal" proof.
The number of symbols of a proof is the sum of the number of characters contained in all of the strings (lines) of the proof; cf. Matos and Antunes (1998).
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REFERENCES
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Douglas R. Hofstadter, Gödel, Escher, Bach: an Eternal Golden Braid, Basic Books, 1979, pp. 33-41 and pp. 261-262.
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LINKS
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FORMULA
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If A369173(n,k) contains no zeros and 3+2^m ones (for m >= 0), then T(n,k) = 2^(m+3) + 25*m + 2.
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EXAMPLE
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Triangle begins:
[2] 2;
[3] 13 13 5;
[4] 94 94 47 94 47 47;
[5] 75 75 31 75 31 31 75 31 31 31 10;
...
For the theorem MIU (310), which is given by A369173(3,2), the "normal" proof is MI (31) -> MII (311) -> MIIII (31111) -> MIU (310), which consists of a total of 13 symbols (counting only M, I and U characters): T(3,2) is therefore 4.
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MATHEMATICA
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MIUDigitsW3[n_] := Select[Tuples[{0, 1}, n - 1], !Divisible[Count[#, 1], 3]&];
MIUProofSymbolCount[t_] := Module[{c = Length[t], nu = Count[t, 0], ni}, ni = 2*nu+c; c += nu(nu+c+2); While[ni > 1, If[OddQ[ni], c += (7*ni+3)/2 + 13; ni = (ni+3)/2, c += ni/2 + 1; ni/=2]]; c+1];
Map[MIUProofSymbolCount, Array[MIUDigitsW3, 7, 2], {2}]
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CROSSREFS
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Cf. A369587 (analog for shortest proofs).
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KEYWORD
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nonn,tabf
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AUTHOR
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STATUS
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approved
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