%N Let r+i*s be the sum, with multiplicity, of the first-quadrant Gaussian primes dividing n; sequence gives r values (with a(1) = 0).
%C A Gaussian integer z = x+iy is in the first quadrant if x > 0, y >= 0. Just one of the 4 associates z, -z, i*z, -i*z is in the first quadrant.
%C The sequence is fully additive.
%H Michael Somos, <a href="/A078458/a078458.txt">PARI program for finding prime decomposition of Gaussian integers</a>
%H <a href="/index/Ga#gaussians">Index entries for Gaussian integers and primes</a>
%e 5 factors into the product of the primes 1+2*i, 1-2*i, but the first-quadrant associate of 1-2*i is i*(1-2*i) = 2+i, so r+i*s = 1+2*i + 2+i = 3+3*i. Therefore a(5) = 3.
%Y Cf. A078458, A078909-A078911, A080088, A080089.
%A _N. J. A. Sloane_, Jan 11 2003
%E More terms and information from _Vladeta Jovovic_, Jan 27 2003