正整数数列An瞒住:An+3=An+2(An+1+An),An+1大于等于An,n=1,2,3,……
问题描述:
正整数数列An瞒住:An+3=An+2(An+1+An),An+1大于等于An,n=1,2,3,……
已知A6=8820,A7=多少
An+1为1个整体,如N=1时,就为A2
答
An+3=An+2(An+1+An)AA4=A3(A2+A1)A5=A4(A3+A2)A6=A5(A4+A3)相乘得到A6=A3(A2+A1)(A3+A2)(A4+A3)将A4代入并提取公因式化简A6=(A1+A2)(A1+A2+1)(A2+A3)*A3^2=8840=20*21^2=4*5*21^2(A1+A2)(A1+A2+1)必然带...