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JUNEAU, Alaska (AP) -- The father of Bristol Palin's son is seeking at least equal custody.

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Levi Johnston filed a petition for custody last month.

Johnston, in his court filing, says he wants 4-year-old Tripp to be in his mother's life and father's life equally.

Palin's attorney says that as of Oct. 15, the Child Support Services Division reported that Johnston owed about $66,000 in back support.

Palin and Johnston were thrust into the national spotlight as expectant, unwed teenagers in 2008, when Palin's mother, Sarah Palin, was tapped as the Republican vice presidential candidate.

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Johnston and Bristol Palin had an on-off relationship before splitting for good. He has since married and has a daughter.

Palin has appeared in several reality series, including one for Lifetime that documented her life as a single mom.