
COMMENTS

Among the first 51 terms only three terms are prime: SmBackConSq(2), SmBackConSq(3), SmBackConSq(14), found by Micha Fleuren.
The next term a(4) is formed from concatenation of square of numbers from 700 to 1 and consists of 3742 digits.  Shyam Sunder Gupta, Jul 25 2013
Analogously, a(5) is probably the concatenation of squares up to 2818^2, which is a probable prime of 18269 digits, while a(6) > 10^40000.  Giovanni Resta, Jul 22 2013
