+72 A sequence of positive integers with a_1 = 1 and a_9 + a_{10} = 646 is formed so that the first three terms are in geometric progression, the second, third, and fourth terms are in arithmetic progression, and, in general, for all n≥1, the terms, a_{2n-1}, a_{2n}, a_{2n + 1} are in geometric progression, and the terms, a_{2n}, a_{2n + 1}, and a_{2n + 2} , and are in arithmetic progression. Let a_n be the greatest term in this sequence that is less than 1000. Find a_n.
+655 I am a little confused on the notations, can you please use latex? Then I can attempt the problem
+26397 A sequence of positive integers with a_1 = 1 and a_9 + a_{10} = 646 is formed so that the first three terms are in geometric progression, the second, third, and fourth terms are in arithmetic progression, and, in general, for all n≥1 , the terms, a_{2n-1}, a_{2n}, a_{2n + 1} are in geometric progression, and the terms, a_{2n}, a_{2n + 1}, and a_{2n + 2} , and are in arithmetic progression. Let a_n be the greatest term in this sequence that is less than 1000. Find a_n.
see link: https://web2.0calc.com/questions/a-sequence_11
