Mathematics teacher in Focsani discovers calculation formula, which he publishes in international encyclopedia

Mihai Teodor, a mathematics teacher at a high school in eastern Focsani, discovered a formula for computing the sum of the products of the digits of all the numbers from 1 to n, which he published in an international encyclopedia of prime numbers.

"I discovered the calculation formula about two years ago. It's about discovering the sum of the products of the digits of all the numbers up to a given number. This was very well known and it's not at all difficult to prove with the help of a computer for a specific 'n'. However, for any value of 'n', the computer scientist can no longer solve this problem and it is up to the mathematician, who can only do so if he discovers the formula and then proves it. Or this hadn't been discovered yet," Mihai Teodor told AGERPRES.

After discovering the formula, the first thought was to publish it in a famous encyclopedia of prime numbers, but this was not without worries, as the professor confesses. The problem had to be published first in a specialty magazine in the country, and then, for two months, the problem was analyzed by mathematicians, and not only from around the world, to see if anyone had previously had a similar idea. Mathematics teacher in Focsani discovers calculation formula, which he publishes in international encyclopedia

"I sent the result to an online American encyclopedia, The On-Line Encyclopedia of Integer Sequences (OEIS). It's a vast encyclopedia of all prime numbers. There's no prime number that hasn't been listed here. They replied that if the problem was previously published in an ISSN publication, then they would consider it. This year, in February, the calculation formula was published in Gazeta Matematica no. 2/2022. Again, I turned to the OEIS, who studied the problem carefully and told me that they would be proposing it for analysis to all the people worldwide for two months, in order to check and see if anyone else previously had a similar contribution or idea. For two months I was very anxious, but finally, on June 5, it was published in this encyclopedia," said the mathematics teacher.

Math teacher Mihai Teodor's problem can be consulted by anyone on QEIS, the calculation formula being numbered with the code A061076.

Mihai Teodor teaches at the "Alexandru Ioan Cuza" National College in Focsani and, according to the teaching staff, he has a remarkable activity in the classroom, with outstanding student results.