What is the best squence for 1 2 4 3 6 8 7 14 16?

Answer 1

That would depend on your definition of "best".

One "obvious" sequence is to cycle through the three operations:

1. multiply by 2
2. add 2
3. subtract 1

starting with a first number of "1".

Then:

• use step 1 on the first number to get the second number (1 x 2 = 2), then
• use step 2 on the second number to get the third number (2 + 2 = 4), then
• use step 3 on the third number to get the fourth number (4 - 1 = 3), then
• use step 1 on the fourth number to get the fifth number (3 x 2 = 6), then
• use step 2 on the fifth number to get the sixth number (6 + 2 = 8), etc