05a. [Saint-Petersburg 1998] Let denote the number of positive divisors of the number . Prove that the sequence does not become strictly monotonic from some point onwards.
05b. PEN J11 Prove that does not become monotonic from any given point onwards.
Archive for February, 2008
05. On the monotonicity of the divisor function.
Posted in Problem of the Bi-Week on February 27, 2008 | Leave a Comment »
S04 A hidden symmetry
Posted in PEN Solutions Archive on February 21, 2008 | Leave a Comment »
04. PEN I11 (Korea 2000) Let be a prime number of the form . Show that
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04. A hidden symmetry
Posted in Problem of the Bi-Week on February 14, 2008 | Leave a Comment »
O4. PEN I11 (Korea 2000) Let be a prime number of the form . Show that
