\(1\times2+2\times5+3\times8+4\times11+...+n(3n-1)=?\)
This app is also available in stereo:
\(1\times2+2\times5+3\times8+4\times11+...+n(3n-1)=?\)
This app is also available in stereo:
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Created on: 2007
Last update: 2023-05-04 11:36:21+0100
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
