This seems to indicate this to be the case:
‘ - The Passport Holders from Korea, Japan, Russia and the Scandinavian nations (as Norway, Denmark, Sweden, and Finland) do not need a visa to Vietnam if they intend to stay in the country within 15 days.’
Dear Christian vK,
Vietnam offers 15-day visa exemptions with single entry for visitors from Norway.. However, their
passports should have at least six months of validity upon the date of arrival to meet airlines’
requirements, and their arrival date is NOT within 30 days from their last exit date with visa exemption.
Otherwise, they will need a Vietnam visa.
If you stay more than 15 days please apply for Vietnam visa
For any further details, please contact us at firstname.lastname@example.org or call us at +84.327.117.119
Stepfano Tran (Mr.)