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I considered a_n as a product of all past terms then used telescoping to say a_(n+1)=(n+2)(n+1)/2Same method just a different starting point
Nice. I worked just from the title board, and spotted that a1 = 1 a2 = 3 a3 = 6 a4 = 10and then verified the induction that a_n = n (n+1) / 2.Took about the same time as your method, so no particular advantage to either.
I considered a_n as a product of all past terms then used telescoping to say a_(n+1)=(n+2)(n+1)/2
Same method just a different starting point
Nice.
I worked just from the title board, and spotted that
a1 = 1
a2 = 3
a3 = 6
a4 = 10
and then verified the induction that
a_n = n (n+1) / 2.
Took about the same time as your method, so no particular advantage to either.