The integer part of the second n is 6+00-(1/2-1/4+1/6-1/8+1/0- ...
Extract10-(1-1/2+1/3-1/4+1/5-...-1. . . . 1/(49*50)) So 10-3.xxxx So the integer part is 6.
The integer part of the third n is 98, because19 * 81-19 * 79 = 38, 18 * 82- 18 * 80 = 36. . . . 11* 89-1* 87 = 22, 10 * 90- 10 * 88 = 20, so we set19× 88 = 20.
99*n/(n+38+36+).....+22+20)=99*n/(n+290)
Because 290 is small relative to n, it can be equal to about 98.
The integer part of the fourth lane A is 1, the original formula, etc. 1- 1/2+ 1/3+ 1/4+ 1/4.。 . + 1/20 13- 1/20 14+ 1=2- 1/20 14
The fifth direct calculation