Indig Numbers and the Power of the Powers of Two represent or create or determine octave. The only difference between one octave and any other octave is the power of two, all other factors being the same. In real vibratory terms this means a halving of length to increase by an octave or doubling of length to decrease by an octave.
Multiplicant determines relative placement, tone, note or degree of modulation or differentiation within the octave derived from the fundamental or tonic. The only arithmetical difference between one tone and any other tone within an octave is the relative value of the multiplicand.
A fundamental is a whole harmonic note from which all other notes of that octave are derived. In deriving these notes it is differentiated much like Undifferentiated White Light is refracted (differentiated) into its constituent colors. Russell says of this Undifferentiated White Light:
There is nothing extraordinary in this. It is another fact which gives this one its importance, and that is that the musical system is composed of three fifths rising one out of another; so this note by 3/4 becomes the root not only of a chord, but the root of all the three chords, of which the middle one is the tonic; the chord of the balance of the system, the chord of the key; the one out of which it grows, and the one which grows out of it, being like the scales which sway on this central balance-beam. Thus F takes its place, C in the center, and G above. These are the 3 fifths of the system on its masculine or major side. The fractions for A, E, and B, the middle notes of the three chords, are 4/5, 3/5, and 8/15; this too tells a tale; 5 is a new ingredient; and as 3 gives fifths, 5 gives thirds. From these two primes, 3 and 5, along with the integer or unit, all the notes of the system are evolved, the octaves of all being always found by 2. When the whole system has been evolved, the numbers which are the lengths of the strings in the masculine or major mode are the numbers of the vibrations of the notes of the feminine or minor mode; and the string-length-numbers of the minor or feminine are the vibration-numbers of the notes of the major or masculine mode. These two numbers, the one for lengths and one for vibrations, when multiplied into each other, make in every case 720; the octave of 360, the number of the degrees of the circle. [Scientific Basis and Build of Music, page 76]