Sorry  Diaconis web page doesnt list such a paper and I let the question of what this alleged paper was stand on talkErdsBacon number for two weeks before deciding to make my correction  Looking it up now it was originally a technical report and it was posthomously part of a book of lectures  Thus it is debatable whether Diaconis published with Erds  However by the definition given on Erds number that it merely be a mathematical paper with common authors in this case a technical report it qualifies