free copy
@CRGreathouse your number
https://mersenneforum.org/showthread.php?t=25929
390644893234047643
sqrt(390644893234047643/2)=441692991 -> 441692991 ; 441692989 ;441692987 ; 441692985
sqrt(390644893234047643) =625015914 -> 625015913 ; 625015911 ;625015909 ; 625015907
(390644893234047643-3)/8-Q-[4-(441692985-7)*(441692985-5)/8]=441692985*X
(390644893234047643-3)/8-P-[4-(625015907-7)*(625015907-5)/8]=625015907*X
Q=441692985*x+152029391
P=625015907*y+60099037
p*(q-625015907)/8=625015907*y+60099037 ,p*q=390644893234047643
p=625015921-8*y
q*(p-441692985)/8=441692985*x+152029391,p*q=390644893234047643
q=884426299- 8*x
Use LLL alghorithm to find one solution of
m*(a1)*(a3)+n*(b1)*(b3) = N*t +T
m*(a1)*(a4)-n*(b1)*(b4) = N*s + S
m*(a2)*(a3)-n*(b2)*(b3) = N*w + W
64 < T <= 64 *j where j is integer > 1
0<S <= sqrt(N)
0<W <= sqrt(N)
a1=441692985 , a2=152029391 ,a3=625015907 ,a4=60099037
b1=8 , b2=884426299 , b3=8 , b4=625015921