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 A353147 #16 Apr 27 2022 07:44:28
%S A353147 0,1,13,157,2127,25547,331007,4172107,52305307,647665707,10216432707,
%T A353147 122621414707,1473657200707,20126330410707,241540165130707,
%U A353147 3120702223570707,37450626705270707,473627744665470707,6125757360430070707,75533532545361070707
%N A353147 Decimal repunits written in base 8.
%F A353147 a(n) = A007094(A002275(n)).
%o A353147 (PARI) a(n) = fromdigits(digits((10^n-1)/9, 8));
%o A353147 (Python)
%o A353147 def a(n): return 0 if n == 0 else int(oct(int("1"*n))[2:])
%o A353147 print([a(n) for n in range(13)]) # _Michael S. Branicky_, Apr 26 2022
%Y A353147 Cf. A002275, A291962, A353142, A353143, A353144, A353145, A353146, A353148.
%Y A353147 Cf. A007094, A023001.
%K A353147 nonn,base,easy
%O A353147 0,3
%A A353147 _Seiichi Manyama_, Apr 26 2022