TARDIS tight schedule, which led to Brachacki leaving the show due to disagreements with the production team and possibly a feeling that he had been given an impossible task. Despite his leaving the show and mixed reactions as to how the set looked (producer Verity Lambert liked it but director Waris Hussein did not), the basic design of the hexagonal console and wall roundels has persisted to the present day. In the Third Doctor serial "The Time Monster" (1972), the console room of the TARDIS was dramatically altered, including the wall roundels. This new set, designed by Tim Gleeson, was disliked
Centered hexagonal number in materials logistics management, for example, in packing round items into larger round containers, such as Vienna sausages into round cans, or combining individual wire strands into a cable. The sum of the first centered hexagonal numbers is . That is, centered hexagonal pyramidal numbers and cubes are the same numbers, but they represent different shapes. Viewed from the opposite perspective, centered hexagonal numbers are differences of two consecutive cubes, so that the centered hexagonal numbers are the gnomon of the cubes. (This can be seen geometrically from the diagram.) In particular, prime centered hexagonal numbers are cuban primes. The