Question 1055729
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 5 9 13 20 29 40 53

1<sup>2</sup>+4 = 1+4 = 5
2<sup>2</sup>+4 = 4+4 = 8    <-- 2nd term should have been 8, not 9
3<sup>2</sup>+4 = 9+5 = 14
4<sup>2</sup>+4 = 16+4 = 20
5<sup>2</sup>+4 = 25+4 = 29
6<sup>2</sup>+4 = 36+4 = 40
7<sup>2</sup>+4 = 49+4 = 53

So the second term should be 8, not 9.
It must have been a typo.  All the terms but the 2nd 
one fit the pattern of  a<sub>n</sub> = n<sup>2</sup>+4.

Edwin</pre>