%N Primes p of the form 4k+1 for which s=26 is the least positive integer such that sp-(floor(sqrt(sp)))^2 is a square.
%C For all primes of the form 4k+1 not exceeding 10000 the least integer s takes only values: 1, 2, 5, 10, 13, 17, 26. These values are the first numbers in A145017 (see our conjecture at A145047).
%e a(1)=6569 since p=6569 is the least prime of the form 4k+1 for which sp-(floor(sqrt(sp)))^2 is not a square for s=1..25, but 26p-(floor(sqrt(26p)))^2 is a square (for p=6569 it is 225).
%Y Cf. A145016, A145017, A145022, A145023, A145043, A145047, A145048, A145049.
%A _Vladimir Shevelev_, Sep 30 2008, Oct 03 2008