Latteral thinking puzzle
 

Complete this finite series.

5, 1 , 2, 5 , 7,...

Spoilerise the important parts of your answers.

No takers? I will reveal the next element in the series.

Next element is : 3

again this is a finite series. This is a lateral thinking problem, so you can never solve it with math (although math can help).

There are [spoiler]12[/spoiler] elements in this series.

Obviously nobody is interested......

So here is the answer:
[spoiler]Numeric representation of the day of the week for the first day of the month for this year.[/spoiler]

I use a shifted version of that sequence to quickly calculate the day of the wee for any day.
1, 4, 4, 0, 2, 5, 0, 3, 6, 1, 4, 6
is easy to remember
144, 025, 036, 146

Add the number of the day in the month and also 2 for 2003, 4 for 2004, 5 for 2005, 6 for 2006, 0 for 2007

calculate the result mod 7, then convert

0 for saturday, 1 for sunday, 2 for monday...