Midweek puzzle - just for fun

Miscellaneous and Personal Stuff I Must Share
1

Following Biotops lead, here’s a puzzle I made up during a slow spot at work. Hope you like it.

The Sequence Spewing Supercomputer

The sequence spewing supercomputer is a brand new invention of mine. If you were to input any number into the machine it will spew out a self contained sequence (By this I mean it will give you a sequence which cannot be added to). However, each of the sequences it spews out is also in sequence. In other words, the separate sequences produced by the machine follow a special pattern all their own. However, as I said, first you have to input a number. Well, as it turns out, I have already inputted two numbers and the sequence spewing supercomputer has processed these numbers and spat out the following two sequences in return:

Sequence 1: 1,4,7,8,9,6,3,2
Sequence 2: 1,4,7,5,3,6,9

If the first number that was inputted was 15, can you:

A) Tell me which number I punched into the Sequence Spewing Supercomputer in order to make it generate the second sequence?

B) Tell me which number I should punch in, in order to make it generate a third sequence which will follow the same pattern as the 1st & 2nd sequences?

C) Tell me what that third sequence would be?

Explain your logic.

I’ll give hints on request.

2

I am confused about the relationship of the sequences. Do you mean that the sequence, which is self-contained, continues by the imputting of another number. Or, do you mean that the sequences relate to the imputted numbers in a sequencial manner independent of the imputted numbers?

I notice that in the first sequence we have a +3, +3, +1, +1, -3, -3, -1. The values of these numbers together add up to 15 if we ignore the +/-.

In the next sequence, these +/- would add up to 16. Was that the second number imputted?

Is any of this relative to the actual solution?