CREATE TABLE table_73654 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "U.S. viewers  ( million ) " CLOB, "Original air date" CLOB)

How many episodes in the season had 3.81 million US viewers?
SELECT COUNT("No. in season") FROM table_73654 WHERE "U.S. viewers (million)" = '3.81'
SELECT COUNT("No. in season") FROM "table_73654" WHERE "U.S. viewers (million)" = '3.81'