Super-d Numbers Revisited

For some reasons, a search for super-$d$ numbers failed to initially discover a previous post on the topic from February 22nd, 2022. Consequently, some of the content in that post has been repeated. Here is the earlier post titled Super-d Numbers. It's a good idea to view both posts as each contains certain content that isn't repeated in the other. The number of posts in this blog now exceeds 500 so it's easy to forget about previous posts. I need to be thorough in the tags that I add to each post.

Here is the new post created when I wasn't aware of the earlier post. 

For $d=2, \dots,9$, a super-$d$ number is a number $n$ such that $d \cdot n^d$ contains a substring made of $d$ digits $d$. For example, 261 is a super-3 number since $3\cdot261^3=5\underline{333}8743$.

I was reminded of these numbers because my diurnal age today, 27019, is a super-2 number since $2 \cdot 27019^2=14600527\underline{22}$. Figure 1 shows a table of the initial $d$-numbers for values of $d$ from 2 to 9.

Figure 1:  source

Figure 2 shows the initial palindromic super-$d$ numbers for values of $d$ from 2 to 6.

Figure 2: source

The frequency of super-$d$ numbers decreases as the value of $d$ increases. The numbers in the range up to 40,000 are 4377, 420, 43, 12, 1, 0, 0, 0 for $d$ = 2, 3, 4, 5, 6, 7, 8, 9 respectively. For me, a forthcoming super-6 number, and the only one is the range up to 40,000, is 27257 with the property that:

$$6 \cdot 27257 \, ^6=2460478505381 \underline{666666} 506497894$$ Here is a Permalink to the calculation.