1* 0^2 + 2*0^2 + 3*0^2 + 4*5^2 = 100.
1* 0^2 + 2*6^2 + 3*2^2 + 4*2^2 = 100.
1* 1^2 + 2*2^2 + 3*3^2 + 4*4^2 = 100.
1* 1^2 + 2*2^2 + 3*5^2 + 4*2^2 = 100.
1* 1^2 + 2*4^2 + 3*1^2 + 4*4^2 = 100.
1* 1^2 + 2*6^2 + 3*3^2 + 4*0^2 = 100.
1* 2^2 + 2*4^2 + 3*0^2 + 4*4^2 = 100.
1* 2^2 + 2*4^2 + 3*4^2 + 4*2^2 = 100.
1* 3^2 + 2*0^2 + 3*3^2 + 4*4^2 = 100.
1* 3^2 + 2*0^2 + 3*5^2 + 4*2^2 = 100.
1* 3^2 + 2*6^2 + 3*1^2 + 4*2^2 = 100.
1* 4^2 + 2*0^2 + 3*4^2 + 4*3^2 = 100.
1* 4^2 + 2*2^2 + 3*2^2 + 4*4^2 = 100.
1* 4^2 + 2*4^2 + 3*4^2 + 4*1^2 = 100.
1* 4^2 + 2*6^2 + 3*2^2 + 4*0^2 = 100.
1* 5^2 + 2*0^2 + 3*5^2 + 4*0^2 = 100.
1* 5^2 + 2*2^2 + 3*1^2 + 4*4^2 = 100.
1* 5^2 + 2*4^2 + 3*3^2 + 4*2^2 = 100.
1* 5^2 + 2*6^2 + 3*1^2 + 4*0^2 = 100.
1* 6^2 + 2*0^2 + 3*0^2 + 4*4^2 = 100.
1* 6^2 + 2*0^2 + 3*4^2 + 4*2^2 = 100.
1* 7^2 + 2*2^2 + 3*3^2 + 4*2^2 = 100.
1* 7^2 + 2*4^2 + 3*1^2 + 4*2^2 = 100.
1* 8^2 + 2*0^2 + 3*0^2 + 4*3^2 = 100.
1* 8^2 + 2*2^2 + 3*2^2 + 4*2^2 = 100.
1* 8^2 + 2*4^2 + 3*0^2 + 4*1^2 = 100.
1* 9^2 + 2*0^2 + 3*1^2 + 4*2^2 = 100.
1*10^2 + 2*0^2 + 3*0^2 + 4*0^2 = 100.
So a(4) = 28.
|