Challenge No. 538: An emirp (prime spelled backward = emirp) number is a prime number and its reversal is also a prime number but this is not a palindromic prime.
Solved using: Python in Excel.
MAP
Applies a function to each element of one or more arrays in Excel.
Next Palindrome with Repeats
Challenge No. 534: Find the next 3 Palindrome numbers for the given numbers where any digit is repeated by the numbers given in Repeats column.
Solved using: Python in Excel.
Signed Number String Sum
Challenge No. 529: Extract the numbers and sum them along with their signs.
Solved using: Python in Excel.
Index-wise Base Encoding Sort
Challenge No. 527: Convert every digit from right to left in the base of its index + 1 reading index 1, 2.
Solved using: Python.
Complete Square by X Placeholder
Challenge No. 524: Fill in the digit marked as X to make the number a perfect square.
Solved using: R.
Sum of Odd Numbers Sequence
Challenge No. 522: Check if a number can be expressed as a sum of consecutive odd numbers.
Solved using: Python in Excel.
List Dates with Unique Digits
Challenge No. 521: List all dates containing unique digits between 1900-01-01 to 2999-12-31.
Solved using: Python in Excel.
Matching Digit Sums
Challenge No. 519: Find first 25 numbers starting with two digits where sum of individual digits of (Number = Square of Number = Cube of Number)
Ex.
Solved using: Python.
Smallest Product Digit Number
Challenge No. 516: Find the smallest numbers whose product of digits is equal to numbers in column A.
Solved using: Python in Excel.
Max 2×2 Grid Sum
Challenge No. 514: Find the 2×2 grids in the given 5×5 grid where sum is the maximum.
Solved using: Python in Excel.