triangular number

Thus too, he played games with triangular numbers, showing the way they built up one on top of the other.

The digital root of a triangular number is 1, 3, 6 or 9.

Each sequence is a multiple of the triangular numbers plus 1.

A square number is also the sum of two consecutive triangular numbers.

The positive difference of two triangular numbers is a trapezoidal number.

The mathematical triangular number series used for scoring is simply delicious.

It is a triangular number and so is its square (36).

Triangular number is the number of entries in such an array.

The simplest example of this is the sequence of square triangular numbers.

For example, the centered square numbers are four times the triangular numbers plus 1.

Otherwise, it is the difference of two triangular numbers:

The number of rectangles in a square grid is given by the squared triangular numbers.

Four is the second square number, the second centered triangular number.

All prices in auctions, as well as for purchases, are based on the triangular numbers.

Five times a heptagonal number, plus 1 equals a triangular number.

This means that one finds 3, 31, 311, 3111, 31111... in the triangular numbers.

Those already in the hotel will be moved to room , or the th triangular number.

The column formed by the set of rightmost rooms will correspond to the triangular numbers.

For example, the digital root of 12, which is not a triangular number, is 3 and divisible by three.

The nth tetrahedral number is the sum of the first n triangular numbers.

Moving inwards, the next pair of diagonals contain the triangular numbers in order.

That makes 666 a triangular number.

Bitwise rotate each of the 25 words by a different triangular number 0, 1, 3, 6, 10, 15, .

Every triangular number is of the form t(t + 1)/2.

The generating function for the square triangular numbers is: