Sorry, mis-created series formula:
A1 = 85
r = 1
A76 = a1 + r * (n - 1) = 160
S76 = [n * (n + 2 * a1 -1)] / 2 = 9321

BTW, we must create all combinations of 561 elements taken 76 by 76,
whose number is:
C561,76 > 215385 * 10^90

Mission impossible!

Bruno