4
$\begingroup$

Find the next number in this sequence:

2, 4, 6, 9, 14, 18, 25, 32, 44, ?

Bonus question: I originally was going to use a different related sequence which grew at a faster rate, but changed it to this one instead. What was the original sequence, and why might I have opted for this one instead?

$\endgroup$

1 Answer 1

8
$\begingroup$

The next number is

63

The sequence seems to be

$a_n = F_n + P_n$, the $n$-th Fibonacci number plus the $n$-th prime number

0+2, 1+3, 1+5, 2+7, 3+11, 5+13, 8+17, 13+19, 21+23, so the next number is 34+29

And my guess for bonus,

perhaps you originally multiplied, but didn't like that because it'd have been more obvious if we'd factored the numbers

$\endgroup$
1
  • 1
    $\begingroup$ Correct on all accounts. That was exactly my reasoning for the bonus question. $\endgroup$
    – TTT
    Feb 1, 2016 at 22:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.