The Erdős–Pósa property forms a pivotal concept in modern graph theory by establishing a profound duality between the problems of packing and covering cycles or other substructures. At its core, this ...

Last week’s installment on columnar transposition ciphers described a formula for the underlying permutation for a CTC. If we assume that the number of columns being used divides the length of the ...

To calculate the rate of change we first need to know the change, or difference, from the previous point for each value. These calculations and answers are shown in the table below. 0 hours 24 hours ...