Tokyo stocks opened higher Tuesday supported by buybacks following heavy selling the previous day, with exporters lifted by the yen’s decline against the U.S. dollar. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 422.12 points, or 1.11 percent, from Monday to 38,341.67. The broader Topix index was up 24.86 points, or 0.94 percent, at 2,670.80. On the top-tier Prime Market, gainers were led by securities house, nonferrous metal and machinery issues. At 9 a.m., the dollar fetched 143.71-72 yen compared with 143.57-67 yen in New York and 142.37-39 yen in Tokyo at 5 p…