Question 1147261
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{{{a[n]}}} = {{{1 + (-1)^(n+1)}}},   n = 1, 2, 3, 4, 5, 6.




Another possible formula, that works, too, is


{{{a[n]}}} = {{{1 + cos(n*pi)}}},  n = 1, 2, 3, 4, 5, 6.
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