Divisible by 12: a^3 + b^3 = c^2
James Buddenhagen
jbuddenh at earthlink.net
Wed Oct 27 15:33:42 CEST 2004
Re sequences relating to a^3 + b^3 = c^2 where a and b are prime
and c is a positive integer, I have submitted several new sequences,
and added to yours (Hugo's), A098970. They are related as follows:
a: A099806 these primes are -1 mod 12
b: A099807 these primes are 1 mod 12
c/12: A098970 your sequence.
sqrt((a+b)/48): A099808
sqrt((a^2-a*b+b^2)/3) A099809, so
corresponding to the factorization a^3+b^3 = (a+b)*(a^2-a*b+b^2),
i.e. corresponding to c^2 = (a+b)*(a^2-a*b+b^2) one has:
(12*A098970)^2 = (48*A099808^2) * (3*A099809^2).
The 48*3 gives 12^2, i.e. the 12 in your c/12 sequence.
Best regards,
Jim Buddenhagen
P.S. Please double check for correctness, typos etc.
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