Fibonacci

Leonardo of Pisa, also known as Fibonacci probably had no idea what he started when he posed a problem about rabbits propogating in an ideal situation in his Liber Abaci. The solution to his problem is a sequence of numbers now know as the Fibonacci sequence in his honor, which starts 1, 1, 2, 3, 5, 8, ... and continues with each subsequent number computed as the sum of the previous two numbers.The Fibonacci sequence even has a journal dedicated to its applications, The Fibonaaci quarterly.

Phi is the symbol used to represent the Golden Ratio. Two quantities have the Golden ratio if the ratio of the their sum to the larger value is the same as the ratio of the larger to the smaller. Mathematically the Golden Ratio is (1+sqrt(5))/2 or about 1.618. The ratio of consecutive Fibonacci numbers approaches the Golden Ratio.

Stamps

Stamp	Description
	Macao, 1.5p, 2005 Scott: 1235 A287 a
	Macao, 2.0p, 2005 Scott: 1235 A287 b
	Macao, 2.5p, 2005 Scott: 1235 A287 c
	Macao, 3.5p, 2005 Scott: 1235 A287 d
	Macau, 10. 2007
	Liechtenstein, 100. 2013 Fibonacci numbers
	Liechtenstein, 260. 2013 Ratios of consecutive Fibonacci numbers
	Liechtenstein, 400. 2013 The Golden Ratio