30-14

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by beny » Sat Aug 25, 2007 2:41 pm
Answer B:

a3 = a2 + 2*a1 = 1 + 2 = 3
a4 = a3 + 2*a2 = 3 + 2 = 5
a5 = a4 + 2*a3 = 5 + 6 = 11
a6 = a5 + 2*a4 = 11 + 10 = 21
a7 = a6 + 2*a5 = 21 + 22 = 43