## Vigenere Subsequence Analyzer

This page will take the ciphertext resulting from an application of a Vigenere Cipher, and with
some presumed key length $k$, produce and analyze the sequence of every $k^{th}$
letter starting with the indicated position. The analysis will include calculating
the frequency of each letter in the subsequence, and finding dot products with rotated
versions of English frequencies.

*Note: As a matter of notation, if English letter frequencies are given by $$(a,b,...,z) = (0.082, 0.015, ..., 0.001)$$ then
$$v0 = (0.082, 0.015, ..., 0.001)\\v1 = (0.001, 0.082, 0.015, ...)$$*