7,23,55,109,191,__  Pick one.
A) 304 B) 305 C) 306 D) 307 E) 308
7= 2^3-1^2   23= 3^3-2^2   55= 4^3-3^2   ....   ..191= 6^3 - 5^2 = 216-25   next number = 7^3-6^2= 343 -36= 
<gadget id="calculator">343 -36</gadget>
<output>307</output>
307   ANSWER:307
<result>D</result>
7,23,55,109,191,__