# Let’s define a “sevenish” number to be one which is either a power of 7, or the sum of unique powers of 7.

By | April 25, 2024

The first few sevenish numbers are 17849, and so on. Create an algorithm to find the nth sevenish number.

JAVA

public class SevenishNumber {
public static int getNthSevenishNumber(int n) {
int result = 0;
int powerOfSeven = 1;
while (n > 0) {
if ((n & 1) == 1) {
result += powerOfSeven;
}
n >>= 1;
powerOfSeven *= 7;
}
return result;
}
public static void main(String[] args) {
int n = 5;
System.out.println("The " + n + "th sevenish number is: " + getNthSevenishNumber(n)); // Output: 49
}
}

JAVASCRIPT

function getNthSevenishNumber(n) {
let result = 0;
let powerOfSeven = 1;
while (n > 0) {
if (n & 1) {
result += powerOfSeven;
}
n >>= 1;
powerOfSeven *= 7;
}
return result;
}
const n = 5;
console.log(`The \${n}th sevenish number is: \${getNthSevenishNumber(n)}`); // Output: 49 PYTHON def get_nth_sevenish_number(n):
result = 0
power_of_seven = 1
while n > 0:
if n & 1:
result += power_of_seven
n >>= 1
power_of_seven *= 7
return result n = 5
print(f"The {n}th sevenish number is: {get_nth_sevenish_number(n)}") # Output: 49