Numerical/Alphabetic Lookup Table Letter Value Letter Value A 0 O 14 B 1 P 15 C 2 Q 16 D 3 R 17 E 4 S 18 F 5 T 19 G 6 U 20 H 7 V 21 I 8 W 22 J 9 X 23 K 10 Y 24 L 11 Z 25 M 12 26 N 13 ! 27 ? 28 Multiplicative Functions A function is multiplicative if it is true that f (mn) = f (m)f (n) if (m, n) = 1. We define τ (n) as the number of positive divisors of an integer n (including 1 and n) and σ(n) as the sum of these same positive divisors. We define φ(n) as the number of integers less than n which are relatively prime to n. Legendre Symbol Rules: a p ! ab p ! 1. If a ≡ b (mod p) then a2 p 2. If p6 | a then ! = b p ! = a p . ! = 1. 3. If p6 | a and p6 | b then b p ! . 4. If p and primes and p ≡ q ≡ ! q are odd ! ! 3 (mod 4) ! then p q p q =− , otherwise = . q p q p ! 5. 1 p 6. −1 p 7. 2 p = 1, ! ( = ! ( = 1 −1 1 −1 if p ≡ 1 (mod 4) if p ≡ 3 (mod 4) if p ≡ 1, 7 (mod 8) if p ≡ 3, 5 (mod 8) Duodecimal Times Tables 5 6 7 8 9 δ 2 δ 10 12 14 16 18 1δ 3 13 16 19 20 23 26 29 4 18 20 24 28 30 34 38 5 21 26 2 34 39 42 47 6 26 30 36 40 46 50 56 7 2 36 41 48 53 5δ 65 8 34 40 48 54 60 68 74 9 39 46 53 60 69 76 83 δ 42 50 5δ 68 76 84 92 47 56 65 74 83 92 δ1 10 50 60 70 80 90 δ0 0 11 55 66 77 88 99 δδ Small Primes: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97