# Number sequence 5

Fill in the correct number in this sequence:

5 3 8 9 1 27 ?

The options are: 18, 54, 38, 14 or 13.

I can see the pattern of 3, 9, 27 but other than that I am clueless.

Source: a publicly available practice test in a book for an IQ-test I got via a friend in the Netherlands.

• I added more explanation on the source. – Dennispuz Nov 16 '18 at 12:34
• Upon first observation, it seems like there are two sequences; there is the 3, 9, 27 pattern alternating with a pattern that adds three to each term, ignoring the tens. Unfortunately, the answer must apparently include tens so that is a circumstantial relationship. – kanoo Nov 16 '18 at 21:12
• I also noticed that the sequence includes each digit between 1 and 9 exactly once, except 4 and 6, in case that means anything. – kanoo Nov 16 '18 at 21:13
• It seems I found similar question without 27.. According to the Online Encyclopedia of Integer Sequences: oeis.org/search?go=Search&language=english&q=5,3,8,9,1.. next number is sequence might be 1 or 3.. – CR241 Nov 22 '18 at 0:13
• @Dennispuz You completely missed my point. If 1 really was part of the sequence, those other options would make no sense at all. But with 11, they at least make some sense (as wrong answers). It's only because you now know that 14 is the correct answer that you can say that the other options are wrong, and why. Before that, you were "clueless" (according to your question). Those other options will only mislead someone who doesn't already know the answer. – ekhumoro Jan 3 '19 at 0:11