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 A095250 #10 Jun 19 2022 11:16:06
%S A095250 0,1,0,3,1,3,1,7,0,1,1,3,1,11,6,7,1,9,1,11,6,11,1,15,11,11,0,19,1,21,
%T A095250 1,7,12,11,16,27,1,11,33,31,1,21,1,11,36,11,1,39,36,11,9,19,1,27,1,39,
%U A095250 54,11,1,51,1,11,27,7,61,33,1,23,42,61,1,63,1,11,36,47,23,39,1,71,0,11,1,63
%N A095250 a(n) = 11111111... (n times) = (10^n-1)/9 reduced mod n.
%C A095250 a(p) = 1 if p is a prime; a(3^k) = 0.
%D A095250 Amarnath Murthy, "On the divisors of Smarandache Unary Sequence", Smarandache Notions Journal, 1-2-3, vol. 11, 2000.
%H A095250 Harvey P. Dale, <a href="/A095250/b095250.txt">Table of n, a(n) for n = 1..1000</a>
%F A095250 a(n) = A002275(n) mod n.
%e A095250 1111111 mod 7 = 1.
%t A095250 Table[Mod[FromDigits[PadRight[{},n,1]],n],{n,90}] (* _Harvey P. Dale_, Jun 19 2022 *)
%o A095250 (PARI) a(n) = (10^n - 1)/9 % n; \\ _Michel Marcus_, Jul 03 2019
%Y A095250 Cf. A002275.
%K A095250 nonn
%O A095250 1,4
%A A095250 _Amarnath Murthy_, Jun 17 2004