Inspired by fibonacci series sanket decided to create is own series which is 1,2,3,7,7,22,15,67,.... what number come immediately before 67?

• the series is a combination of two series...
  First one is 1, 3, 7, 15, 31, 63, ... (2^n - 1, n = 1, 2, 3, ...)
  Second one is 2, 7 (= 2 + 5), 22 (= 7 + 5*3), 67 (= 22 + 5*3*3), 202 ( = 67 + 5*3*3*3), ...
  Combining, we get 1, 2, 3, 7, 7, 22, 15, 67, 31, 202, 63, ...
  So, if it is number before 67, then it is 15 and if it is number after 67, then it is 31, followed by 202 and so on...
• 13 years agoHelpfull: Yes(38) No(5)
• combination of 2 series ,1,3,7,15,31
  Answer is 31
• 13 years agoHelpfull: Yes(10) No(7)
• the ans will be 31
  2n+1
• 13 years agoHelpfull: Yes(6) No(5)
• 15. as it is asked number before 67.
• 13 years agoHelpfull: Yes(5) No(16)
• 1,2,3,.......67=31
• 7 years agoHelpfull: Yes(0) No(1)
• 31 is the next number
• 5 years agoHelpfull: Yes(0) No(0)