Problem 55710. AZPC Oddly Triangular: N=34/304 using Digits 3/7/9 Part 4 of 5
AZPC created the Oddly Triangular contest on 9/7/22. The challenge is to find the longest sequence of N odd digits such that sum(1:value) is composed of only odd digits. The contest ended on 9/8/22 as Rokicki created a 3.6 million digit solution with the implication that an infinite length pattern had been determined. [N=2, 17, sum(1:17)=153]
Part 4 is the generalization of multiple solutions to find Rokicki's result.
Reviewing the N=7/10/13 3/7/9 solutions determine a form such that N=4+3*n.
The values 397979797973 and 399799799799799733 has N=6+6*n given the generalization of 39[n]79[n]79[n]79[n]79[n]73[n]
Usage of matlab java math can be seen in the Test Suite. A function zcombvec is given in the function template to facilitate creation of all vectors that only use the 3/7/9 digits. Usage of zcombvec is not required.
M=OddlyTri4p3n_379(N) where N=digit length, M is a string of length N.
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