perplexus.info :: Sequences : Number Alert

Number Alert (Posted on 2003-02-27)

Two numbers are missing in this pattern:

2, 4, 11, 37, 153, ??, ???

What are they?

See The Solution Submitted by ashley

Rating: 2.1111 (9 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

Solution

Comment 14 of 14 |

Let S(n) = nth term of the sequence.

Then, the relationship between successive terms of the sequence is given by:

S(i+1) =i*S(i) +i+1

So, that: S(2) = 1*S(1)+2 =1*2+2=4

S(3)= 2*S(2)+3=11

S(4)=3*S(3)+4= 37

S(5)= 4*S(4)+5=153

Consequently, the missing terms are:

S(6)= 5*S(5)+6=5*153+6=771

and: S(7) = 6*771+7= 4633

Posted by K Sengupta on 2021-12-13 00:12:16

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