# Equal+number

101

**42 (number)**— ← 41 43 → 42 ← 40 41 42 43 44 45 46 …102

**17 (number)**— ← 16 18 → 17 ← 10 11 12 13 14 15 16 …103

**Square number**— In mathematics, a square number, sometimes also called a perfect square, is an integer that can be written as the square of some other integer; in other words, it is the product of some integer with itself. So, for example, 9 is a square number,… …104

**24 (number)**— For other uses, see 24 (disambiguation). ← 23 25 → 24 ← 20 21 22 23 …105

**Crossing number (graph theory)**— A drawing of the Heawood graph with three crossings. This is the minimum number of crossings among all drawings of this graph, so the graph has crossing number cr(G) = 3. In graph theory, the crossing number cr(G) of a graph G is the… …106

**Computable number**— In mathematics, particularly theoretical computer science and mathematical logic, the computable numbers, also known as the recursive numbers or the computable reals, are the real numbers that can be computed to within any desired precision by a… …107

**8 (number)**— Evolution of the glyphIn the beginning, various groups in India wrote eight more or less in one stroke as a curve that looks like an uppercase H with the bottom half of the left line and the upper half of the right line removed. At one point this …108

**19 (number)**— ← 18 20 → 19 ← 10 11 12 13 14 15 16 17 …109

**Congruent number**— In mathematics, a congruent number is a positive integer that is the area of a right triangle with three rational number sides.[1] A more general definition includes all positive rational numbers with this property.[2] The sequence of integer… …110

**Narcissistic number**— In recreational number theory, a narcissistic number[1][2] (also known as a pluperfect digital invariant (PPDI),[3] an Armstrong number[4] (after Michael F. Armstrong)[5] or a plus perfect number) …