Irrational Numbers from Adjacent Natural Numbers (Part IXb)

Staircase Sequences of Irrational Numbers Derived from (n((xkyk) + x + y)

This is a continuation of Part IXa for n((xkyk) + x + y).

It has been shown (Between_two_Rational_Numbers on Wiki) that between two real numbers (ℝ) there exists an irrational number. Accordingly, it will be shown here that between two adjacent natural numbers (ℕ) there exists an irrational number (ℝ\ℚ). In addition, an arithmetic progression or sequence of irrational numbers will be generated in this section where there are two common differences (Δ1) and (Δ2) between the irrational numbers generated from n((xkyk) + x + y). So, therefore, let's proceed as follows:

The sequence derived from the equation n((xkyk) + x + y) where k = 2 is shown in Table I, and that for k = 3 is shown in Table II where the values of n range from 1 to 10, while those of x and y range, respectively, from 1 to 20 and 2 to 21. The differences (Δ1) and (Δ2) between the irrational numbers are, respectively, about 0.5 and 1.5 where Δ2 corresponds to the end of one Δ1 to the start of the next Δ1 in the sequence, and approach these values as x and y increase without bound. The value for each n((xkyk) + x + y), is calculated to 6 decimal places, is irrational and each of these values indeed falls between their respective consecutive natural numbers. In addition, the fourth column heading is SQRT = n((xkyk) + x + y).

Table I Irrational Sequence (k=2)
nx y SQRTΔ1/Δ2
1121.802776
1232.3333330.530558
2343.8890871.555754
2454.3909000.501812
3565.9231191.532219
3676.4190410.495922
4787.9411901.522150
4898.4356680.494478
59109.9523871.516719
5101110.4466370.494251
6111211.9600031.513366
6121312.4544140.494411
7131413.9655191.511105
7141514.4602140.494695
8151615.9696981.509484
8161716.4647050.495007
9171817.9729741.5082687
9181918.4682850.495312
10192019.9756101.507325
10202120.4712070.495596
Table II Irrational Sequence (k=3)
nx y SQRTΔ1/Δ2
1121.767767
1232.3013680.533601
2343.8527591.551390
2454.3616510.508892
3565.8937351.532084
3676.3944670.500733
4787.9170501.522583
4898.4148280.497778
59109.9320191.517191
5101110.4286420.496623
6111211.9424261.513784
6121312.4386160.496190
7131413.9500751.511459
7141514.4461500.496075
8151615.9559331.5097827
8161716.4520410.496108
9171817.9605621.508521
9181918.4567720.496210
10192019.9643121.507540
10202120.4606540.496342

If the natural numbers are plotted on a grid vs n the following picture of a staircase is obtained. The blue lines are the Δ1 differences of 0.5 within the run of the staircase, while the black diagonal, is the difference Δ2 of 1.5; the red, in addition, is a jump from one level to the next (the rise of the staircase). Note that both sequences can be displayed using the same figure.

Picture of a staircase

Is still possible to write out the as one line sequence (for the first ten natural numbers, in red) for k = 2:

1, 1.802776, 2, 2.333333, 3, 3.889087, 4, 4.390900, 5, 5.923119, 6, 6.419041, 7, 7.941190, 8, 8.435668, 9, 9.952387, 10, 10.446637

and for k = 3:

1, 1.767767, 2, 2.301368, 3, 3.852759, 4, 4.361651, 5, 5.893735, 6, 6.394467, 7, 7.917050, 8, 8.414828, 9, 9.932019, 10, 10.428642

In the staircase sequence the n is required in order that the irrational numbers fall between their two adjacent natural numbers. It wasn't expected that the irrational numbers fell right smack-dab in the same general areas as shown in the figure. In addition, connecting all the 0.25 terms together and all the 0.75 terms together gives "rise" to two parallel ramps where the sequence may have both ramp and staircase properties depending on the view.

Go to Part Xa and Part Xb for n((−xkyk) + x + y) staircase sequences.
Go back to Part IXa for proofs for n((xkyk) + x + y).

Go to Part I or Part IV for non-staircase methods. Go back to homepage.


Copyright © 2026 by Eddie N Gutierrez. E-Mail: enaguti1949@gmail.com