Question

an = 3a(n − 1) + 6 and a1 = 1

a4=87
a5=249

this is what I got but the answer were incorrect in the sequence.

Answer 1

Did you post this question under the name of Fay?

http://www.jiskha.com/display.cgi?id=1439188422

a(1) = 1
a(2) = 3 a(1) + 6 = 3(1) + 6 = 9
a(3) = 3 a(2) + 6 = 3(9) + 6 = 33
a(4) = 3 a(3) + 6 = 3(33) + 6 = 105
a(5) = 3 a(4) + 6 = 3(105) + 6 = 321