Introduction
To determine whether an n-digit number N is a Keith number, create a Fibonacci-like sequence that starts with the n decimal digits of N, putting the most significant digit first. Then continue the sequence, where each subsequent term is the sum of the previous n terms. By definition, N is a Keith number if N appears in the sequence thus constructed.
As an example, consider the 3-digit number N = 197. The sequence goes like this:
- 1, 9, 7, 17, 33, 57, 107, 197, 361, ...
Because 197 appears in the sequence, 197 is seen to be indeed a Keith number.
Read more about this topic: Keith Number
Famous quotes containing the word introduction:
“Such is oftenest the young mans introduction to the forest, and the most original part of himself. He goes thither at first as a hunter and fisher, until at last, if he has the seeds of a better life in him, he distinguishes his proper objects, as a poet or naturalist it may be, and leaves the gun and fish-pole behind. The mass of men are still and always young in this respect.”
—Henry David Thoreau (18171862)
“For better or worse, stepparenting is self-conscious parenting. Youre damned if you do, and damned if you dont.”
—Anonymous Parent. Making It as a Stepparent, by Claire Berman, introduction (1980, repr. 1986)
“For the introduction of a new kind of music must be shunned as imperiling the whole state; since styles of music are never disturbed without affecting the most important political institutions.”
—Plato (c. 427347 B.C.)