# Program for number sequence cracking

This is a general question which I'm not really quite sure is appropriate here so before you decide to down vote, just drop me a message that it's not appropriate and it will be promptly removed or relocated.

Now on the question:
Are there any programs that can crack most number sequences for the purposes of finding the answer? I often purchase second hand puzzle books, and they often don't have answers in them or the rule for any given nth term. The problem is when I encounter a sequence I can't solve, I don't have a solution to work off or a AP/GP rule to work off of. So the focus of the question is are there any programs that can be given an input and give possible answers and possibly a rule, although the rule is unnecessary, as I can work that out myself.

Many thanks in advance.

• I think OEIS is a great source... – ABcDexter Jun 18 '16 at 5:18
• I personally like your question and asking about puzzle-making or solving as a process is absolutely okay on site. However, asking for what are best resources of XY are generally not appreciated on StackExchange (opinion based) so, I'm curious how this question will fare on Puzzling... You might consider switching over to the meta-site though. There is a post about puzzle solving sources. – BmyGuest Jun 18 '16 at 6:13
• any partial sequence of $n$ terms can be fitted to a polynomial or order $n-1$ – Jasen Jun 18 '16 at 6:36
• @Jasen You are absolutely right (it's called Extrapolation). – ABcDexter Jun 18 '16 at 6:42
• In a general case, Douglas Hofstatder wrote about a program he was working on called seek-whence to do this. – Ross Millikan Jun 18 '16 at 15:21

There are some good number sequence problems which do not come under standard AP,GP,HP or AGP or any other well known mathematical sequence/pattern. Also, there are some stupid so-called "sequences" which are meant to be not solved but use that lateral-thinking part of our brains.