8 = 1 − 23 − 45 + 6 + 78 − 9
8 = 9 − 8 + 76 − 5 − 43 − 21
8 = 0^5 + 1^9 − 2^7 − 3^8 + 4^6 + 5^3 + 6^0 + 7^4 + 8^2 + 9^1
8 = 2^2 + 2^2
8 = 4 ÷ 4 × 4 + 4 = 4.4 − .4 + 4
28 - 1 = 3 * 5 * 17
8 × 1 + 1 = 9
8 × 12 + 2 = 98
8 × 123 + 3 = 987
8 × 1234 + 4 = 9876
8 × 12345 + 5 = 98765
8 × 123456 + 6 = 987654
8 × 1234567 + 7 = 9876543
8 × 12345678 + 8 = 98765432
8 × 123456789 + 9 - 987654321
8 = 2^3 and 9 = 3^2 are the only consecutive powers, (Mihăilescu's theorem / Catalan's Conjecture )
Strobogrammatic number: the same upside down.
Number k such that 8*10^k - 49 is prime (799999951).
Number k for which k!/9 + 1 is Prime, 8!/9 + 1 = 4481
Number k such that (k! + 3)/3 is prime
Numbers k such that k^2 divides 9^k - 1 (43046720)
Number k such that 9^k + 8^(k-1) is prime.
Number of squarefree graphs on 4 vertices
Cake number, maximal number of pieces resulting from 3 planar cuts through a cube (or cake)
Numbers of edges of regular polygon constructible with unmarked straightedge and compass.
Maximal number of regions obtained by joining 4 points around a circle by straight lines
Sqrt(8) = 2 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/(4 + 1/(1 + 1/...)))))))))))))))))
Representations, Binary to Hexadecimal:
1000_2
22_3
20_4
13_5
12_6
11_7
10_8
8_9
8_11
8_12
8_13
8_14
8_15
8_16
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
