Rev. Charles David Sherrer, C.S.C. died on April 13, 2017, at Holy Cross House, Notre Dame, Indiana. Born on September 21, 1935, in Marion, Ohio, he was 81 years old.

Sherrer served University of Portland at different times as an English literature instructor, residence hall assistant, pastor, faculty and chairman of the English Department, dean of the graduate school and academic vice president. After retirement, he remained at UP until last January when he moved to Holy Cross House at Notre Dame.

Sherrer was a gracious, humble and kind person who was a great leader and resource for the UP community.

In his honor, I constructed the following brainteasers:

1. Sherrer died on 4/13/2017 where the sum of the digits of 4132017 equal 18, which is the reverse of 81, the age he died.

2. Moreover, if Sherrer’s full birthdate 9/21/1935 is split as 921 and 1935, the product of the digits of 921 and the sum of the digits of 1935 each equal 18, respectively.

3. If 4132017, the day Sherrer died, is split as 41, 32, 01, and seven, the sum of these four numbers equal 81, the age he died.

4. Sherrer died this year on 4/13 where the difference of four and 13 equal the month number of his birth (nine) and twice four plus 13 yield the day number of his birth (21).

5. Further, the difference of 9 and 21 equal the product of the digits of 4/13.

6. Also, the reverse of 4/13 is 314 which correspond to the first three digits of number Pi.

7. If 2017 is split in the middle as 20 and 17, the difference of these two numbers equal three. If on the other hand 2017 is split into its even- and odd-numbered digits as 21 and 07, these two numbers differ by 14. Note that three and 14 side by side give 314 and the reverse of 314 is 4/13, the day Sherrer died in 2017.

8. Twice the difference of the squares of four and 13 equal 306 and the 306th prime number is 2017.

9. Additionally, 413 equal seven times 59 where these two prime numbers differ by 52 which interestingly equal 4 x 13. Also, seven and 59 add to 66 which equal the sum of the numbers assigned to the letters of Fr. Sherrer’s first name, Charles.

10. If numbers 1 to 26 are assigned to the letters of the English alphabet as A being one, B being two, C being three, etc., the sum of the numbers assigned to the letters of Charles Dave Sherrer equal 189 which equal nine times 21 where nine and 21 together make 9/21, the day Sherrer was born in 1935.

11. The sum of the numbers assigned to the letters of Charles David Sherrer equal 197 where the sum of the digits of 197 equal 18, which is the reverse of 81, the age Fr. Sherrer died. Furthermore, the product of the digits of 197 is 63 and three times the 63rd prime number, namely 307, yield 921, Sherrer’s birth date, September 21.

12. If 921 is split as 9 and 21, the 9th and 21st prime numbers, namely 23 and 73, put side by side give 2373 which equal 3 times 791 where the reverse of 791 is 197 (Charles David Sherrer).

13. If Sherrer’s birth year 1935 is split as 19 and 35, the sum of these two numbers is 54 where the reverse of 54 is 45 and the 45th prime number is 197. Further, 1935 equals 45 times 43 where 43 times the sum of its digits, namely seven, equal 301 where the reverse of 301 is 103 and Sherrer died on the 103rd day of 2017.

14. Moreover, 1935 equal 129 times 15 where the reverse of 129 is 9/21 (Sherrer’s birth date) and the reverse of 15 is 51 which equal 17 times three where 17 plus three is 20, 17 minus three is 14, three and 14 side by side give 314, 20 and 17 together make 2017, and the reverse of 314 side by side with 2017 yield 4/13/2017, the day Sherrer died.

15. Lastly, the prime factors of Sherrer’s 81st birthday expressed as 9212016, namely two, three, 11, 73, and 239, are the first, second, fifth, 21st, and 52nd prime numbers where the sum of one, two, five, 21, and 52 coincidentally equal 81.

*Aziz Inan is a professor of electrical engineering teaching at University of Portland and he can be reached at ainan@up.edu.*