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 A327294 #36 Sep 21 2019 14:39:34
%S A327294 28,2368,22326868,2222332366866868,22222222333322326666886866866868,
%T A327294 2222222222222222333333332222332366666666888866866666886866866868
%N A327294 a(n) = (A325907(n) + 1) * (10^(2^(n-1)) - A325907(n)).
%C A327294 a(n) is composed of digits {2,3,6,8}.
%F A327294 a(n) = 2 * (10^(2^n) + 3 * 10^(2^(n-1)) - 4)/9 - 2 * A325493(n-1) + A325910(n-1) * 10^(2^(n-1)).
%e A327294 a(1) = 2 * 10^1 + 8.
%e A327294 a(2) = 23 * 10^2 + 68.
%e A327294 a(3) = 2232 * 10^4 + 6868.
%e A327294 a(4) = 22223323 * 10^8 + 66866868.
%e A327294 a(5) = 2222222233332232 * 10^16 + 6666886866866868.
%e A327294 And
%e A327294 2 = 2 * (10^1 - 1)/9 + 0.
%e A327294 23 = 2 * (10^2 - 1)/9 + 1.
%e A327294 2232 = 2 * (10^4 - 1)/9 + 10.
%e A327294 22223323 = 2 * (10^8 - 1)/9 + 1101.
%e A327294 2222222233332232 = 2 * (10^16 - 1)/9 + 11110010.
%e A327294 And
%e A327294 8 = 8 * (10^1 - 1)/9 - 2 * 0.
%e A327294 68 = 8 * (10^2 - 1)/9 - 2 * 10.
%e A327294 6868 = 8 * (10^4 - 1)/9 - 2 * 1010.
%e A327294 66866868 = 8 * (10^8 - 1)/9 - 2 * 11011010.
%e A327294 6666886866866868 = 8 * (10^16 - 1)/9 - 2 * 1111001011011010.
%o A327294 (Ruby)
%o A327294 def A(n)
%o A327294 a = [3, 6]
%o A327294 b = ([[3]] + (1..n - 1).map{|i| [a[i % 2]] * (2 ** (i - 1))}).reverse.join.to_i
%o A327294 (b + 1) * (10 ** (2 ** (n - 1)) - b)
%o A327294 end
%o A327294 def A327294(n)
%o A327294 (1..n).map{|i| A(i)}
%o A327294 end
%o A327294 p A327294(6)
%Y A327294 Cf. A325907, A325910, A325493, A327266.
%K A327294 nonn
%O A327294 1,1
%A A327294 _Seiichi Manyama_, Sep 16 2019