Nonetheless, in the years following 1789, Tetens begun another career as a high-ranking Danish civil servant: member of the Finanzcollegium in Copenhagen, then (1791) counselor of state, and (1803) co-director of the state bank and director of the widow pension funds. By this time, he was interested in pure mathematics as well as in applications. His interest in polynomial algebra was influenced by his belonging to the German combinatorial school of Carl Friederich Hindenburg, Christian Kramp and others.