Octodecimal

Octodecimal 1249 is equivalent to decimal 6561 or nonary 10000.

The decimal scheme should have been made a duodecimal, or better a quinquedecimal or octodecimal one; the expansive system would need a more than India-rubber elasticity to include all the whimsical creations of an author's brain.

By studying other number system such as unodecimal (base-11), duodecimal (base-12), tridecimal (base-13), quadrodecimal (base-14), pentadecimal (base-15), heptadecimal (base-17), octodecimal (base-18), nonadecimal (base-19) and vigesimal (base-20), researcher will gain a better understanding of how number systems work in general.

Traditional number system — binary, octal, decimal and hexadecimal, in regular use and Strange number system, with an extra edge of memorized information with greater density, zero redundancy problem, avoiding sign problem and reducing complexity of interconnections, - unodecimal, duodecimal, tridecimal, quadrodecimal, pentadecimal, heptadecimal, octodecimal, nona decimal, vigesimal and further are discussed through compliments.

I say very considerably greater than, because only a certain number of the terms which satisfy the required conditions of order and weight actually appear in the octodecimal invariant in question.

18 modes of archery and use of other implements of war (Adavuyal and Ayudhet prayogangal), 18 kinds of manners and customs (Nattacharangal) and there seems to be something of importance in this octodecimal division.

it is reasonable to suppose that a warmer temperature will be manifest as from the octodecimal apex 1957-58, and will subsequently continue.

Of course all symmetrical invariants have an invariable sign ; but this is not the case with skew invariants, as for example, M. Hermite's octodecimal invariant of a binary quintic, which will change its sign with that of the determinant of transformation.