2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69882We study the generating function for the number of involutions on $n$ letters containing exactly $r\gs0$ occurrences of 3412. It is shown that finding this function for a given $r$ amounts to a routine check of all involutions on $2r+1$ letters.12 pages, 4 figuresCombinatorics05A05; 05A15; 05C90text