Choose any string on your guitar and start from the first fret (you can start from any fret )
|1|2|3|4|5|6|7|8|9|10|11|12|
From 1 to 3 is the whole note, and 1 to 2 is the half note.
W = whole note
H = half note
So the formula is -
1-W-W-H-W-W-W-H"
Sa...re...ga...ma...pa...dha...ni...'sa
1...3...5...6...8...10...12...'13