如果把不能被2,3,5,7,11,13整除的正整数称为类质数,那么90000以内有多少类质数?要求精确答案

90000以内有17261个类质数10^10以内有1918081917个类质数10^100以内大约有1.9180819181*10^99个类质数----------------------简解----------------------------------2,3,5,7,11,13的最小公倍数是2*3*5*7*11*13=3003...为什么会知道1-30030有5760个类质数呢？可以用excel筛选如果要列算式,就是:30030-30030/2-30030/3-30030/5-30030/7-30030/11-30030/13+30030/(2*3)+30030/(2*5)+30030/(2*7)+30030/(2*11)+30030/(2*13)+30030/(3*5)+30030/(3*7)+30030/(3*11)+30030/(3*13)+30030/(5*7)+30030/(5*11)+30030/(5*13)+30030/(7*11)+30030/(7*13)+30030/(11*13)-30030/(2*3*5)-30030/(2*3*7)-30030/(2*3*11)-30030/(2*3*13)-30030/(2*5*7)-30030/(2*5*11)-30030/(2*5*13)-30030/(2*7*11)-30030/(2*7*13)-30030/(2*11*13)-30030/(3*5*7)-30030/(3*5*11)-30030/(3*5*13)-30030/(3*7*11)-30030/(3*7*13)-30030/(3*11*13)-30030/(5*7*11)-30030/(5*7*13)-30030/(5*11*13)-30030/(7*11*13)+30030/(2*3*5*7)+30030/(2*3*5*11)+30030/(2*3*5*13)+30030/(2*3*7*11)+30030/(2*3*7*13)+30030/(2*3*11*13)+30030/(2*5*7*11)+30030/(2*5*7*13)+30030/(2*5*11*13)+30030/(2*7*11*13)+30030/(3*5*7*11)+30030/(3*5*7*13)+30030/(3*5*11*13)+30030/(3*7*11*13)+30030/(5*7*11*13)-30030/(2*3*5*7*11)-30030/(2*3*5*7*13)-30030/(2*3*5*11*13)-30030/(2*3*7*11*13)-30030/(2*5*7*11*13)-30030/(3*5*7*11*13)+30030/(2*3*5*7*11*13)= -10331+12673+5112+1866+930-2556-933-360-105-622-240-70-144 -42-30+311+120+35+72+21+15+48+14+10+6-31-10+1=5760