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In mathematics, the Fibonacci numbers, commonly denoted F
n
, form a sequence,
called the Fibonacci sequence, such that each number is the sum of the two preceding
ones, starting from 0 and 1. Fibonacci numbers are strongly related to the golden
ratio: Binet's formula expresses the nth Fibonacci number in terms of n and the
golden ratio, and implies that the ratio of two consecutive Fibonacci numbers tends
to the golden ratio as n increases.
Fibonacci numbers are also closely related to Lucas numbers ,in that the Fibonacci
and Lucas numbers form a complementary pair of Lucas sequences
The beginning of the sequence is thus:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765,
10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811, 514229, 832040,
1346269, 2178309, 3524578, 5702887, 9227465, 14930352, 24157817, 39088169,
63245986, 102334155...
The Lucas numbers or Lucas series are an integer sequence named after the
mathematician François Édouard Anatole Lucas (1842–91), who studied both that
sequence and the closely related Fibonacci numbers. Lucas numbers and Fibonacci
numbers form complementary instances of Lucas sequences.
The Lucas sequence has the same recursive relationship as the Fibonacci sequence,
where each term is the sum of the two previous terms, but with different starting
values. This produces a sequence where the ratios of successive terms approach
the golden ratio, and in fact the terms themselves are roundings of integer powers of
the golden ratio.
[1]
The sequence also has a variety of relationships with the
Fibonacci numbers, like the fact that adding any two Fibonacci numbers two terms
apart in the Fibonacci sequence results in the Lucas number in between.
The sequence of Lucas numbers is:
2, 1, 3, 4, 7, 11, 18, 29, 47, 76, 123, 199, 322, 521, 843, 1364, 2207, 3571, 5778,
9349, 15127, 24476, 39603, 64079, 103682, 167761, 271443, 439204, 710647,
1149851, 1860498, 3010349, 4870847, 7881196, 12752043, 20633239, 33385282,
54018521, 87403803……
All Fibonacci-like integer sequences appear in shifted form as a row of the Wythoff
array; the Fibonacci sequence itself is the first row and the Lucas sequence is the
second row. Also like all Fibonacci-like integer sequences, the ratio between two
consecutive Lucas numbers converges to the golden ratio.