Citing this Record
"United States Census, 1850," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MC1S-42J : accessed 01 Dec 2013), Alansen Andrews, Ridgeway, Orleans, New York, United States; citing dwelling 495, family 506, NARA microfilm publication M432, roll 575.
I'm not sure but maybe possibly Andrews is an Anglicised version of the surname Andrus ? Also, sometimes in that era, last names were also incorrectly transcribed. Best wishes in your search.