Prove this

a^2+b^2=c^2+3
has infinite integer solutions

my progress: prove a and b are even and c odd
also: x^2+y^2=z^2+z+1 (related)

I'm original poster.
>>2
You are an idiot
>>4
It is different for other d values
>>5
Well 0,1,2 obviously; but nonzero...
conciser this..
even number: 2k
odd number: 2k + 1
even number squared:4k^2
odd number squared:4k^2 + 4k + 1
only even^2+even^2=odd^2+3 gives integer triplets
also: all numbers are divisible by four, and c by 8