Sample input points (T(n) vs. n):

 > input := [[1,2],[2,5],[3,10],[4,17],[5,26],[6,37],[7,50],[8,65]];

 (1)

 > with( plots ):

Let's look at T(n) vs. n:

 > plot( input, n=0..8, style=point, symbolsize=15 );

Increasing.  So, ω(1) (bound below by constant, not tightly).  Let's consider T(n)/n vs. n

I'll provide a procedure that can be passed to map.  Given a point [x,y] and a function, e.g., n->n^2, returns the point [x, y/func(x)]

 > applyPoint := proc( point, func )  local x, y;  description "Divides y by func(x)";  x := point[1]; y := point[2];  [ x, y/func(x) ]; end proc:

Here is another function, for your convenience.  Takes a list of points and a function, returns a list of points, [x, y/func(x)]

 > pointMapFamily := proc( points, func )  description "plotPoints( points, func ) plots points (x, func(y))";  map( applyPoint, points, func) end proc:

Take another stab at the data above.  Divide by n:

 > guess_n := pointMapFamily( input, n->n );

 (2)

 > plot( guess_n, n=0..8, style=point, symbolsize=15 );

Nope, still increasing.  So, T(n) = ω(n) (T(n) is bound below by a line, but not tightly)

Try T(n) / n^2:

 > guess_n_2 := pointMapFamily( input, n->n^2 );

 (3)

 > plot( guess_n_2, n=0..8, style=point, symbolsize=15 );

Shoot, going to 0.  Or is it?  Look more closely:

 > plot( guess, n=0..8, 0..3, style=point, symbolsize=15 );

How 'bout that?  Looks as if T(n) =

Let's look at  this with the line y=1

 > ourPoints := plot( guess, n=0..8, 0..3, style=point, symbolsize=15, color=blue ):

 > asym := plot( 1, n=0..10 ):

 > display( { ourPoints, asym } );