mathematics, the doubly triangular numbers are the numbers that appear within the sequence of triangular numbers, in positions that are also triangular numbers...

A triangular number or triangle number counts objects arranged in an equilateral triangle. Triangular numbers are a type of figurate number, other examples...

666 is the largest triangular number that is also a repdigit. Since 36 is a triangular number too, 666 is a doubly triangular number. Also, 666 is the...

triangle (as all triangular and tetragonal numbers appear in it). Because 15 is also triangular, 120 is a doubly triangular number. 120 is divisible...

factoriangular numbers. Doubly triangular number Factorial prime Fibonacci number Lazy caterer's sequence Square triangular number Rayaguru, Sai Gopal; Odjoumani...

natural number following 230 and preceding 232. 231 is a sphenic number. 231 is the 21st triangular number, a doubly triangular number, a hexagonal number, an...

from 1 to 36), and also a doubly triangular number (because 36 is the sum of all numbers up to 8) and the eighth such number (in the series of 1, 6, 21...

the only such doubly strictly absurd number[unreliable source?] 2187 = 37, vampire number, perfect totient number 2188 – Motzkin number 2197 = 133, palindromic...

In mathematics and computing, a triangular array of numbers, polynomials, or the like, is a doubly indexed sequence in which each row is only as long as...

sentences where one of the constituents is a pronoun, in which case it is doubly marked, both by word order and by case inflection, where the subject pronoun...

sums in Floyd's triangle reveals the doubly triangular numbers, triangular numbers with an index that is triangular. 1            = 1 = T(T(1)) 1            =...

counting binary trees and perfect matchings. Exponential factorial Just as triangular numbers sum the numbers from 1 {\displaystyle 1} to n {\displaystyle n}...

progressions in a family of doubly infinite arithmetic progressions have a non-empty intersection, then there exists a number common to all of them; that...

truncation of the great stellated dodecahedron, where the pentagram faces become doubly-wound pentagons ({5/2} --> {10/2}), making the internal pentagonal planes...

space L(p,q). Dihedra have also been called bihedra, flat polyhedra, or doubly covered polygons. As a spherical tiling, a dihedron can exist as nondegenerate...

L_{n-2}=L_{n}-L_{n-1}} , one can extend the Lucas numbers to negative integers to obtain a doubly infinite sequence: ..., −11, 7, −4, 3, −1, 2, 1, 3, 4, 7, 11, ... (terms...

In mathematics, the Perrin numbers are a doubly infinite constant-recursive integer sequence with characteristic equation x3 = x + 1. The Perrin numbers...

meeting at each vertex, and three at each edge. Together they have 96 triangular faces, 96 edges, and 24 vertices. The vertex figure is a cube. The 24-cell...

action of G on the cosets of B is doubly transitive. So (B, N) pairs of rank 1 are more or less the same as doubly transitive actions on sets with more...

tetrahedral cells with 20 meeting at each vertex. Together they form 1200 triangular faces, 720 edges, and 120 vertices. It is the 4-dimensional analogue of...

{\displaystyle n} -dimensional doubly-directed hypercube graph can be routed with edge-disjoint paths. Tuza's conjecture: if the maximum number of disjoint triangles...

languages utilize doubly subscripted arrays (or arrays of arrays) to represent an m-by-n matrix. Some programming languages start the numbering of array indexes...

pentagons from the truncated vertices and 12 decagons taking the form of doubly-wound pentagons overlapping the first 12 pentagons. The latter faces are...

twigs are slender and often pendulous and the leaves are roughly triangular with doubly serrate margins and turn yellow and brown in autumn before they...

0008, MR 1368518 Kolpakov, Alexander; Murakami, Jun (2013), "Volume of a doubly truncated hyperbolic tetrahedron", Aequationes Mathematicae, 85 (3): 449–463...

using an O-III astronomical filter (isolating the wavelength of light from doubly ionized oxygen), as almost all light from this nebula is emitted at this...

notch cuneate cuneatus leaf base Triangular, wedge-shaped, stem attaches to point cuneiform whole leaf Narrowly triangular, widest on the opposite end from...

an upper triangular matrix. The system Q(Rx) = b is solved by Rx = QTb = c, and the system Rx = c is solved by 'back substitution'. The number of additions...

left rotation Double Metaphone double right rotation double-ended queue doubly linked list dragon curve dual graph dual linear program dyadic tree dynamic...

given number of lines passing below them. Roberts's triangle theorem and the Kobon triangle problem concern the minimum and maximum number of triangular cells...