Question

What is the next number in the sequence? Explain your reasoning.
1,4,7,10,...
1,5,9,13,...
3,8,18,38,...
5,8,14,26,...

Answer 1

1,4,7,10,13,16   $a_{n+1}=a_{n}+3$
1,5,9,13,17,21   $a_{n+1}=a_{n}+5$
3,8,18,38,78,158    Add 5, Add 10, Add 20 etc.
5,8,14,16,40,88    Add 3, Add 6, Add 12, Add 24 etc.