Tags » Arithmetic Progression

Integers(a,b,c,d) in A.P. whose number of divisors is also in A.P.


229, 361, 493, and 625 are in arithmetic progression:

361 – 229 = 493 – 361 = 625 – 493 = 132

and the number of divisors of each is also in arithmetic progression: 84 more words

Number Puzzles

A^3 + B^3 + C^3 + D^3 = N^2, (A,B,C,D) in A.P.



A, B, C, and D form an arithmetic progression.
Let d be the common difference.


d = 1 ……..
d = 14 …… … 145 more words

Number Puzzles

Special triplets of 4-digit Prime numbers




1487, 4817, and 8147 are prime numbers such that

>> Each of 4817 and 8147 is obtained by permuting the digits of 1487, and… 118 more words

Prime Numbers

Oblong numbers : x(x+ 1), y(y+ 1), z(z+ 1) in arithmetic progression

An Oblong number is a number which is the product of two consecutive integers, that is, a number of the form



There exist infinitely many triplets of positive integers , for which the numbers… 84 more words

(a,b,c) in AP; a+b, b+c, c+a form a Chain of squares -- Part 2

are chosen so that they form an arithmetic progression and
, , form a Chain of squares

Note the squares in columns and


Here are the first few solutions: 25 more words

Number Puzzles

x^4 + y^4 = z^4 - N with (x,y,z) in arithmetic sequence

with and in arithmetic sequence.


There are solutions of the form:

………. (1, 2, 3), (7, 8, 9)
………. (2, 4, 6), (14, 16, 18) 235 more words

Number Puzzles