CREATE TABLE table_46740 ("Letter" TEXT, "IPv6 address" TEXT, "AS-number" TEXT, "Operator" TEXT, "Location #sites  ( global/local ) " TEXT, "Software" TEXT)

Which location has an AS-number of N/A?
SELECT "Location #sites (global/local)" FROM table_46740 WHERE "AS-number" = 'n/a'
SELECT "Location #sites (global/local)" FROM "table_46740" WHERE "AS-number" = 'n/a'