Hi earboth!

I understand the most part of your explanation, can you go deeper in the meanings of (a,b,c)?

I think it may be related to the order of the sequences.

But I don't understand why a can jump from 1a to 4a

b is the order of the second column, and c is the order of the third, which would then equal 0

Another question

If we would have a sequence with the second column of difference with order of say, 1. The third column of difference would have order zero and we would then considerate T(n) as a cubic expression?

Hi Sudharaka! Thanks for your reply.

I am a little perplexed over how you got

Is this thought over trial and error?

I am amazed how this worked, calculating over n=7 we get the right solution.

Maybe this is a recurrent problem that is easy to calculate?

Thanks again, it's great to see the way that people that at are good with it, think.