This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A348547 #11 Nov 06 2021 06:36:30
%S A348547 1,4,49,524,5596,58706,608886,6267854,64180304,654605898,6656849267,
%T A348547 67539297095,683989985496,6916722312963,69859080168037
%N A348547 Number of positive integers with n digits and final digit 9 that are equal to the product of two integers ending with the same digit.
%C A348547 a(n) is the number of n-digit numbers in A348545.
%F A348547 a(n) < A052268(n).
%F A348547 a(n) = A346952(n) + A348055(n) - A348546(n).
%F A348547 Conjecture: lim_{n->infinity} a(n)/a(n-1) = 10.
%t A348547 Table[{lo, hi}={10^(n-1), 10^n}; Length@Select[Union[Union@Flatten@Table[a*b, {a, 3, Floor[hi/3], 10}, {b, a, Floor[hi/a], 10}], Union@Flatten@Table[a*b, {a, 7, Floor[hi/7], 10}, {b, a, Floor[hi/a], 10}]], lo<#<hi&], {n, 8}]
%o A348547 (Python)
%o A348547 def a(n):
%o A348547 lo, hi = 10**(n-1), 10**n
%o A348547 return len(set(a*b for a in range(3, hi//3+1, 10) for b in range(a, hi//a+1, 10) if lo <= a*b < hi) | set(a*b for a in range(7, hi//7+1, 10) for b in range(a, hi//a+1, 10) if lo <= a*b < hi))
%o A348547 print([a(n) for n in range(1, 9)]) # _Michael S. Branicky_, Oct 22 2021
%Y A348547 Cf. A052268, A346950, A346952, A348054, A348055, A348545, A348546.
%K A348547 nonn,base,hard,more
%O A348547 1,2
%A A348547 _Stefano Spezia_, Oct 22 2021
%E A348547 a(9) from _Michael S. Branicky_, Oct 22 2021
%E A348547 a(10)-a(15) from _Martin Ehrenstein_, Nov 06 2021