Question 586739
Well, this could be a sequence of reciprocals of the antiharmonic sequence [cool, but very unlikely: 1, 1/4, 1/9, 1/16, 1/20, 1/25, 1/36, 1/49, 1/50, 1/64, 1/81, 1/100, 1/117, 1/121, 1/144...], or you typed in the fifth term incorrectly (should it be 1/25?), which makes the nth term 1/n^2. I think the latter is more probable.