Find the rule, add 1 + 2 + 1, 1 + 2 + 3 + 2 + 1, 1 + 2 + 3 + 4 + 3 + 2 + 1 1+2+3+4+… +97+98+99+98+97… +4+3+2+1=______ ．

Find the rule, add 1 + 2 + 1, 1 + 2 + 3 + 2 + 1, 1 + 2 + 3 + 4 + 3 + 2 + 1 1+2+3+4+… +97+98+99+98+97… +4+3+2+1=______ ．

Because 1 + 2 + 1 = 4 = 22; 1 + 2 + 3 + 2 + 1 = 9 = 32; 1 + 2 + 3 + 4 + 3 + 2 + 1 = 16 = 42; it is not difficult to see from the special case that the sum of the numbers in the sequence is equal to the square of the middle number +97+98+99+98+97… +4 + 3 + 2 + 1, = 992, = 9801

Find the value of 2 ^ 99 + 2 ^ 98 + 2 ^ 97 +... + 2 ^ 2 + 2 + 1
According to (A-1) (a ^ 2010 + A ^ 2009 + A ^ 2008 +... + A ^ 2 + A + 1) = a ^ 2011-1, this is a math problem in the second volume of the first grade of junior high school. Please explain it in detail

(2-1)(2^99+2^98+```+2+1)=2^100-1

How about 468 times 1001? It's a simple calculation!

468*1001
=468*(1000+1)
=468*1000+468
=468000+468
=468468