Given the sequence:
[tex]11+17+23+29+35+41[/tex]
This is equivalent to:
[tex](5+6)+(5+12)+(5+18)+(5+24)+(5+30)+(5+36)[/tex]
Or:
[tex](5+6\cdot1)+(5+6\cdot2)+(5+6\cdot3)+(5+6\cdot4)+(5+6\cdot5)+(5+6\cdot6)[/tex]
Now, using "i" as an index, the sum is:
[tex]=\sum ^6_{i\mathop=1}(5+6\cdot i)[/tex]
