Legendre constant is a mathematical constant that appears in the asymptotic expansion of prime number counting function.
2 points: limit =1+1/2+1/4+1/8+... = 2.
This is also a mathematical joke, that is, an infinite number of mathematicians enter a bar, the first mathematician asks for a glass of beer, and the latter asks for the first half. The bartender didn't say anything, but brought two glasses.
3 points: unicode characters, converted to 3.
The fourth point: this is a modular operation. In a cyclic finite field of 7, 2x4 = 8 = 7+ 1 "=" 1, so the reciprocal of 2 should be 4.
5 points: phi= golden ratio =1.618 (2× phi-1) 2 = 5.
6 o'clock: 3! =3*2* 1 series orthogonality
7 points: infinite decimal 6.9, 9 cycles, 6.999999...= 7.
8 o'clock: black dot stands for 1 and white dot stands for binary of 0.
9 o'clock: Quaternary, 2*4+ 1=9.
10: binomial calculation, c (5,2) 2)= 10/0.
1 1 point: 0x stands for hexadecimal, 0B in hexadecimal is equal to 1 1 in decimal, a is 10, b is 1 1, and c is/kloc-0. ...
12 point: issuer
Over.