1*2+2*3+3*4+···+10*11求写过程、急!

1 2 3 4 ·····7 ·······10 ········?1 3 5 7 ·····?······?··········290 1 4 9 ·····?······?··········? 序列 1 2 3 4 5 6 ······ n 对应的数 1 3 6 10 21······? 8+11+14+17+20+·······+305 数学计算题.呜呜呜1+2+3+4+···················+98+99+100+99+98+···············+3+2+1 带有数字的四字词语按顺序1···2···3···4···5···6···7···8···9···10···祝福语 证明1·3·5·····(2n-1)/2·4·6·····2n 急·····················1+2+3+...+999=? 2[4/3y—（2/3y—1/2）]=3/4y急·································!1 这几道奥数题谁会,求2014在哪一行那一列 1 2 3 4 5 10 9 8 7 6 11 12 13 14 15 20 19 18 17 16 求2014哪一行那一列 1 2 3 4 5 6 7 8 9 ···· ····· ·························· 数列 1/2,3/2,1/3 ,4/3,·········1/n+1,n+2/n+1,·········是否有极限? 1+2+3+4+5····+50 1+2++3+··········+10000= 俗语和名句的填空1······,自知之明.2······,行必果.3工欲善其事,······.4临渊羡鱼,······.5非学无以广才,······.6······,福兮祸之所伏.7项庄舞剑,······.8······,人以群 1+2+3+4·······+98+99等于多少 正整数按图的规律排列,请写出第二十行,第二十一列的数 列 行 1 2 5 10 17 4 3 61118 9 8 7 12 19 急列 1 2 3 4 5行 1 2 5 10 17······················ 4 3 6 11 18······················9 带数字1·2·3·4·5·6·7·8·9·10·的成语,每个数字至少三个 怎样计算1×2+2×3+3×4+······+100×101 (1-2)×(2-3)×(3-4)×······×(19-20)= 1+2+3+···+2008?2+3+4+···+2009