# What number should come next?

1 3 10 12 14 21 ◇

Identify ◇

• possibly in OEIS: 16- oeis.org/A283770 11 - oeis.org/A004515 Nov 28, 2018 at 6:27
• one more number added Nov 28, 2018 at 7:53

The next number is

23

Reason:

the numbers are base 5, i.e in decimal they are 1,3,5,7,9,11. The next is 13 in decimal, which is 23 in base 5.

The next number in the sequence is

23

Reason:

Every third number in the sequence is the previous number plus $$7$$ and all rest are previous number plus $$2$$.
So the number next in sequence is $$21+2=23$$.