Hey Guys,

Erm can anyone here give a good explanations regarding explicit and implicit sequences?

For example:

1,1,3,3,5,5,7,7,9,9. I don't know how to derive an implicit formula for the sequence. The answer given by my teacher is a(n)=n ; for n is odd

a(n)=n-1 ;for n is even

p/s:I've googled for almost an hour but the outcome is negative..Hope you guys can help me...Thanks