What is the missing number 4, 8, 10, 11, 13, 15, 17?

My intuitive guess was 6 ; I entered the amended sequence 4 , 6 , 8 , 10 , 11 , 13 , 15 , 17 into The On-Line Encyclopedia of Integer Sequences® (OEIS®) and almost instantly got 9 possible ways to continue that sequence. The top of them was. A291171 Black numbers on the roulette wheel. read more

My intuitive guess was [math]6[/math]; I entered the amended sequence [math]4,6,8,10,11,13,15,17[/math] into The On-Line Encyclopedia of Integer Sequences® (OEIS®) and almost instantly got [math]9[/math] possible ways to continue that sequence. read more