Violins. Equations. Nazis. The opening sequence for National Geographic Channel’s “Genius” has it all and more, fusing a number of intriguing and sometimes disturbing images into a stew of mood-setting tension. The best opening sequences tell you enough to make you watch but not so much that you feel you’ve already watched. Whether it’s the grainy dissolve of scientific formulas or the jolting power of an explosion, this sequence gives audiences the perfect set-up for an impressive mini-series.