Oct 5, 2020 · Prove that some member of the sequence $7, 77, 777, 7777, \dots$ is divisible by $2019$. So far I have figured that as $2019$ is divisible by $3$, then if one of the terms of the sequence $$ …

Nov 14, 2020 · Does ⋮ mean "is divisible by" in mathematical notation? Ask Question Asked 5 years, 3 months ago Modified 2 years, 3 months ago

Mar 26, 2013 · The induction methods is nice because it provides an insight into why this divisibility rule works. However, AFAICS, it only shows that the digit-sum being divisible by 3 is a necessary …

This is the standard way, in the specific meaning of compliance to international standards: ISO 80000-2, clause 2.7-17. Note that the vertical bar character used there is normatively identified as U+2223 …

Jan 1, 2018 · The totient of $210$ - the number of values between $1$ and $210$ that are relatively prime to $210$ - is $ (2-1) (3-1) (5-1) (7-1)=48$. Using this, we can say that there are …

I also see that $6^n$ $- 5n + 4$ is divisible by $5$ which is $6-5+4$ and $7^n$$+3n + 8$ is divisible by $9$ which is $7+3+8=18=9\cdot2$. Are they just a coincidence or is there a theory behind?

That sum 33 is divisible by three and so is the original number 289752. This is not the case when dividing by 2, for example 12 is divisible by two but when its digits are summed (1+2=3) you receive …

Proof by induction that n3 − n n 3 n is divisible by 6 6 Ask Question Asked 12 years, 10 months ago Modified 2 years, 11 months ago

This is equivalent to: Prove that any palindrome with an even number of digits is divisible by 11, and a more general solution is available at: Proof for divisibility rule for palindromic integers of even length.

Jan 21, 2025 · For questions about the structure and properties of a divisible group, which are Abelian groups in which one can "divide" by positive integers.