A pyramidal number is a
*Triangular pyramidal number (three sides)
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pyramidal number — noun A number that represents the number of items in a pyramid having a given number of sides and layers … Wiktionary
Pentagonal pyramidal number — A pentagonal pyramidal number is a figurate number that represents the number of objects in a pyramid with a pentagonal base.MathWorld|title=Pentagonal Pyramidal Number|urlname=PentagonalPyramidalNumber] The n th pentagonal pyramidal number is… … Wikipedia
Square pyramidal number — In mathematics, a pyramid number, or square pyramidal number, is a figurate number that represents a pyramid with a base and four sides. These numbers can be expressed in a formula as:sum {k=1}^nk^2={n(n + 1)(2n + 1) over 6}={2n^3 + 3n^2 + n over … Wikipedia
Heptagonal pyramidal number — A heptagonal pyramidal number is the sum of the first few heptagonal numbers. The heptagonal number for n can be calculated by adding up the heptagonal numbers for 1 to n , or by using the formula n ( n + 1)(5 n 2)/6.The first few heptagonal… … Wikipedia
Hexagonal pyramidal number — A hexagonal pyramidal number is a number formed by adding the first few hexagonal numbers. The first few numbers are::1, 7, 22, 50, 95, 161, 252, 372, 525, 715, 946, 1222, 1547, 1925 OEIS|id=A002412The numbers have the form:{n(n+1)(4n 1)}over6… … Wikipedia
Pyramidal — Py*ram i*dal, a. [Cf. F. pyramidal.] [1913 Webster] 1. Of or pertaining to a pyramid; in the form of a a pyramid; pyramidical; as, pyramidal cleavage. [1913 Webster] The mystic obelisks stand up Triangular, pyramidal. Mrs. Browning. [1913… … The Collaborative International Dictionary of English
Pyramidal numbers — Pyramidal Py*ram i*dal, a. [Cf. F. pyramidal.] [1913 Webster] 1. Of or pertaining to a pyramid; in the form of a a pyramid; pyramidical; as, pyramidal cleavage. [1913 Webster] The mystic obelisks stand up Triangular, pyramidal. Mrs. Browning.… … The Collaborative International Dictionary of English
10000 (number) — Number number = 10000 prev = 9999 next = 100000 range = 10000 100000 cardinal = 10000 ordinal = th ordinal text = ten thousandth numeral = decamillesimal factorization = 2^4 cdot 5^4 prime = divisor = roman = overline|X unicode = overline|X, ↂ… … Wikipedia
20000 (number) — Number number = 20000 range = 10000 100000 cardinal = 20000 ordinal = th ordinal text = twenty thousandth factorization = 2^5 cdot 5^4 bin = 100111000100000 oct = 47040 hex = 4E2020,000 (twenty thousand) is the number that comes after 19,999 and… … Wikipedia
30000 (number) — Number number = 30000 range = 10000 100000 cardinal = 30000 ordinal = th ordinal text = thirty thousandth factorization = 2^4 cdot 3 cdot 5^4 bin = 111010100110000 oct = 72460 hex = 753030,000 (thirty thousand) is the number that comes after… … Wikipedia
