22. (2.4 Sequences and Summations) Select the formula that is used to produce the integer sequence 2,16,54, 128,250,432,686,... a. = 2n", n = 1,2,3,... b. n = 2 + 14n, n = 0,1,2,3,.. c. Un = 2n, n = 0,1,2,3,... d. An = 4 + 14(n-1)-2, n = 1,2,3,... 23. (1.1 Propositional Logic) Determine which compound proposition is true. a. 2+2 = 5 or 1+3 = 2. b. if 1+1 = 2, then 2+3 = 4. c. 2+2 = 4 and 1 + 3 = 2. d. 0 > 1 if and only if 1 > 2. 24. (1.6 Rules of Inference) What rule of inference is used in this argument? Steve will work at a computer company this summer. Therefore, this summer Steve will work at a computer company or he will be a beach bum. a. Modus tollens. b. Modus ponens c. Simplification d. Addition