网址:http://m.1010jiajiao.com/timu_id_267021[举报]
(1)72n-42n-297能被264整除;
(2)an+1+(a+1)2n-1能被a2+a+1整除(其中n,a为正整数).
(2)an+1+(a+1)2n-1能被a2+a+1整除(其中n,a为正整数)
(1)n+(n+1)+(n+2)+…+(3n-2)=(2n-1)2;
(2)22+42+62+…+(2n)2=.