Given any third number, it is easy to find a quadratic equation such it generates the two given numbers and the selected third.
For example,
Un = -100,036.5n2 + 398,783.5n - 296,021 gives U3 = 1
Un = -100,032n2 + 398,770n - 296,012 gives U3 = 10
Un = -99,987n2 + 398,635n - 295,922 gives U3 = 100
Un = -99,537n2 + 397,285n - 295,022 gives U3 = 1000
Un = -95,037n2 + 383,785n - 286,022 gives U3 = 10000
Un = -50,037n2 + 248,785n - 196,922 gives U3 = 100000
and so on.
The question provides no reason to choose one of these rather than another.
What is the the next number in the sequence 1,2,4,7,11,.....
The answer is 137, it is obtained like this:0 + 26 + 1 = 2726 + 27 + 1 = 5427 + 54 + 1 = 8254 + 82 + 1 = 137
The next number in the sequence is 480
The next number could be 26 The next number could be 12 - - - - - - - - - The next number that is in the sequence is 12.
The next number in the sequence will be 56.
Without a sequence given in the question, the next number to 6 is 7.
A single number, such as 122.4832 does not constitute a sequence.
381838 is one number: it does not describe a sequence.
A single number, such as 2726101400, does not make a sequence.
A single number, such as 171422, does not constitute a sequence.
The nest number in the sequence is 18. Note that the difference between each number and the next number in the sequence follows the simple sequence of 1,2,3,4. Obviously the next in the sequence of increases is 5, so 13+5=18.
A signle number does not define a sequence uniquely and so the next number can be any number that you want it to be.A signle number does not define a sequence uniquely and so the next number can be any number that you want it to be.A signle number does not define a sequence uniquely and so the next number can be any number that you want it to be.A signle number does not define a sequence uniquely and so the next number can be any number that you want it to be.