3, 12, 7, 26, 15, ?

• 54
  because there are 2 series running alternatively 2n+1,2n+2
  so sixth term will be 26*2+2 = 54
  and seventh term will be 15*2+1 = 31
  and so on.
• 14 years agoHelpfull: Yes(21) No(3)
• 3, ,7, ,15
  (3*2)+1=7
  (7*2)+1=15
  
  12, ,26, ,?
  (12*2)+2=26
  (26*2)+2=54
  The ans is:54
  
• 14 years agoHelpfull: Yes(13) No(0)
• 7-3=4
  7+8=15
  26-12=14
  
  26+28=54
• 14 years agoHelpfull: Yes(3) No(5)
• 54
  series will continue as
  3,7,26,15,54,31,110,63,222,127,446,255...
• 14 years agoHelpfull: Yes(2) No(2)
• 54
  because there are 2 series running alternatively 2n+1,2n+2
  so sixth term will be 26*2+2 = 54
  and seventh term will be 15*2+1 = 31
  and so on.
• 13 years agoHelpfull: Yes(2) No(0)
• next number in the series is 54.
  
  3,12,(3X2+1),(12X2+2),(7X2+1),(26X2+1).....
• 14 years agoHelpfull: Yes(1) No(0)
• look at the alternative option
  3,7,15
  3*2+1=7
  7*2+1=15
  rest alternative option are generated as
  12*2+2=26
  26*2+2=54
  ans =54
• 13 years agoHelpfull: Yes(1) No(0)
• 42
  power of 9 is added with alternative integers
  
• 14 years agoHelpfull: Yes(0) No(1)
• 42
  power of 9 is added with alternative integers
  
• 14 years agoHelpfull: Yes(0) No(2)
• 42
  power of 9 is added with alternative integers
  
• 14 years agoHelpfull: Yes(0) No(2)
• 42
  power of 9 is added with alternative integers
  
• 14 years agoHelpfull: Yes(0) No(2)
• 42
  power of 9 is added with alternative integers
  
• 14 years agoHelpfull: Yes(0) No(2)
• Consider the terms in alternate manner
  3
  3*2+1=7
  7*2+1=15
  12*2+2=26
  So the next term will be 26*2+2=54
• 8 years agoHelpfull: Yes(0) No(0)