Number of square-triangle (square triangular number)

The calculator calculates the weighted average of the ratings of the following items.              

Converter allows you to convert numbers between number bases - binary (binary), trójkowym, czwórkowym, Friday, szóstkowym, siódemkowym, octal (octal), dziewiątkowym, decimal (decymalnym) jedenastkowym, dwunastkowym, trzynastkowym, czternastkowym, piętnastkowym, hexadecimal (hex). Typed characters that are not numbers and the letters A, B, C, D, E, F are ignored.      

Calculator by entering an angle in degrees or radians calculated values ​​of the basic trigonometric functions.

The calculator can calculate the area of a ​​rectangle.

The program generates the prime numbers in a given range using the sieve of Eratosthenes algorithm.        

Checks the calculator is a large number of so-called gay (Happy Number). Number gay is a natural number is defined as follows: Calculate the sum of squares of digits of the number. Repeat this process for the next results as long as we get the number 1 or the results will be repeated. If you have received as a result of one, the original number is the number of gay. Otherwise, a number bleak.