A series is a set of partial sums of sequences of numbers. A single number, such as 135, does cannot define a series.
The immediate [next] superset is, trivially, the set of natural numbers which consists of the counting numbers and zero. The next significant superset is the set of integers: the counting numbers, their additive inverses (or negatives) and zero.
series
That is a series number...no capacity. The next set of numbers give you the capacity. Generally, Lennox unit numbers equate to their capacity divided by 1000. IE: XXX90 has about 90,000 BTUH capacity...7.5 tons.
By definition, the set of counting numbers starts at one and proceeds in ascending order. The next number is 2. If two were not the next number in the set, it would not be the set of counting numbers.
The next set of numbers after trillion are quadrillion and quintillion
In general, you cannot. You need to know how many numbers there are and then, in only a select few cases can you find the set.
This is called a sequence and if we add the numbers in that sequence it is called a series.
Not necessarily. There are series over all kinds of subsets and supersets of the set of real numbers.
A set of integers and their negative counterparts will have an average of zero.
They are septets.
Start with the natural numbers, 0, 1, 2, ... .Then add the set of negative numbers: this makes up the integers. Next add in the set of ratios of any two integers (the second being non-zero): this makes up the rational numbers. Next add in the set of all numbers which cannot be expressed as terminating or repeating decimal numbers. This is the set of irrational numbers. The rationals and irrationals, together, make up the set of real numbers.