NSNSNSNNSNSS EEEEEWEEWWEWWWEWWW a = -13/20 S_a = -124660942032543/256000000000 ~ -486.9568048146211 | S_{-1} = 5005 binom = 5005
SSSNSNNSNSNNNNSSNS EEEEEEWWEWEEWWEWWWWW a = -2/5 S_a = -63526557090248/1220703125 ~ -52040.95556833116 | S_{-1} = 92378 binom = 92378
a=1 check: True
