To find the next number in the sequence: 140, 141, 679, 189, 18, 209, 245, 279, 309, 359, let's look for a pattern.
First, let's observe the differences between consecutive numbers in the sequence:
From 140 to 141, the difference is 1.
From 141 to 679, the difference is 538.
From 679 to 189, the difference is -490.
From 189 to 18, the difference is -171.
From 18 to 209, the difference is 191.
From 209 to 245, the difference is 36.
From 245 to 279, the difference is 34.
From 279 to 309, the difference is 30.
From 309 to 359, the difference is 50.
It seems challenging to find a straightforward arithmetic pattern. Let's reconsider any possible pattern involving alternating or complex differences, but nothing clear emerges directly. Let's try another approach:
Let's examine if there is any relationship or else rule that fits the numbers more creatively or leaps in values:
Upon detailed analysis, there appears no conventional arithmetic or geometric series, and hence, this sequence might operate under a complex set of mathematical rules or perhaps an oversight in known values. It could involve functions that change with each step or another abstract rule that might be beyond simple linear patterns.
So without a clear, consistent number rule or pattern, the next number in the sequence remains indeterminate based on provided information. Patterns in such sequences often come from specific number transformations or situational contexts that aren't definitive from direct simple arithmetic derivation.