geometric progression

A geometric sequence is a sequence {a_k}, k = 0, 1, ..., such that each term is given by a multiple r of the previous one. Another equivalent definition is that a sequence is geometric iff it has a zero series bias. If the multiplier is r, then the kth term is given by a_k = r a_(k - 1) = r^2 a_(k - 2) = a_0 r^k. Taking a_0 = 1 gives the simple special case a_k = r^k. The Season 1 episode "Identity Crisis" of the television crime drama NUMB3RS mentions geometric progressions.

arithmetic progression | common ratio | geometric series