Pyramidal numbers

(redirected from Pyramidal number)
Also found in: Encyclopedia, Wikipedia.
(Math.) certain series of figurate numbers expressing the number of balls or points that may be arranged in the form of pyramids. Thus 1, 4, 10, 20, 35, etc., are triangular pyramidal numbers; and 1, 5, 14, 30, 55, etc., are square pyramidal numbers.

See also: Pyramidal

References in periodicals archive ?
n] = Triangular Pyramidal number of rank n = n(n + 1)(n + 2)/6
Nichomachus also considered the connections between numbers and three-dimensional geometrical patterns, such as the cubic numbers and the pyramidal numbers.
In this paper we have defined and investigated the s-consecutive, s-reversed, s-mirror and s-symmetric sequences of Pyramidal numbers (Triangular numbers of dimension 3.
The activities on ziggurats and pyramidal numbers also fit in nicely with this syllabus in the components of Measurement: M2 (applications of area and volume) and Algebraic Modelling: AM4 (modelling linear and non-linear relationships).
The difference here is the pentagonal pyramidal numbers [6], so