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19-7=12 37-19=18 61-37=24 由此可見該數列的差是一個等差數列,差數依次為6的倍數, 12.18.24之後是30 36 61+30=91 91+36=127第六行是127 第n行是7+6*(2+3+…+n)=3n^2+3n+1
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