There was much discussion about President-elect Trump using executive orders and presidential memorandums to fulfill his campaign promises. Some presidents haven't made great use of this ability. Harrison issued none. And up until FiIlmore, the most issued by a President was 18 or less. FDR signed the most, 3,728, many more than and other president. Only 2 others past the 1000 mark: Wilson and T. Roosevelt. Since Kennedy, issuances have numbered between 166 (G.W. Bush) to 381 (Regan) for entire terms of the president.
As of March 29th, President Trump is at 46. To find out what they are visit Presidential Actions at the WhiteHouse.gov site which lists all his executive orders and presidential memos.
(Both executive orders and presidential memos are directives issued by the executive branch. The main difference between the two is presidents typically cite their legal authority in executive orders, but not in presidential memos.)
For past executive orders and presidential memos check in the TIGER catalog.