notebook/notes/algebra/sequences/square-numbers.md

5.3 KiB

title TARGET DECK FILE TAGS tags
Square Numbers Obsidian::STEM algebra::sequence
algebra
sequence

Overview

The n$th term of the **square numbers** (s_n)_{n \geq 0} is $n^2. The first few terms are $0, 1, 4, 9, 16, 25, 36, 49, 64, \ldots$

%%ANKI Basic What shape do gnomons associated with square numbers take on? Back: L-shapes. Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic How are gnomons of the square numbers visualized? Back: !square-gnomon.png Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic What general term refers to the different colored segments in the following? !square-gnomon.png Back: Gnomons. Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic What are the first five square numbers (s_n)_{n \geq 0}? Back: 0, 1, 4, 9, 16 Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic How is square number 16 graphically depicted? Back:

* * * *
* * * *
* * * *
* * * *

Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic What closed formula is used to find the $n$th square number? Back: n^2 Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic What is the recurrence relation in the recursive definition of square numbers (s_n)_{n \geq 0}? Back: s_n = s_{n-1} + (2n - 1) Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI What is the initial condition(s) in the recursive definition of square numbers (s_n)_{n \geq 0}? Back: s_0 = 0 Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731. END%%

%%ANKI Basic How is the n$th square number $s_n represented with sigma notation? Back: s_n = \sum_{k=1}^n (2k - 1) Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic Which polygonal numbers are the "next" generalization of triangular numbers? Back: The square numbers. Reference: “Triangular Number,” in Wikipedia, January 13, 2024, https://en.wikipedia.org/w/index.php?title=Triangular_number&oldid=1195279122.

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%%ANKI Cloze The sum of {1:natural numbers} is to {2:triangular numbers} whereas the sum of {2:odd natural numbers} is to {1:square numbers}. Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic What polygonal number is k equal to after the following for loops?

int k = 0;
for (int i = 1; i <= n; ++i) {
  k += 2 * i - 1;
}

Back: The $n$th square number. Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

%%ANKI Basic Why are square numbers a sum of odd numbers? Back: The gnomon of a square number is twice the width of the previous square, plus the corner. Reference: “Square Number,” in Wikipedia, May 10, 2023, https://en.wikipedia.org/w/index.php?title=Square_number&oldid=1154182731.

END%%

Bibliography