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 A262154 #19 Jul 25 2021 02:40:40
%S A262154 4,8,31,57,111,144,247,347,444,627,651,754,825,854,861,1261,1264,1371,
%T A262154 1457,1681,1811,2102,2331,2531,3338,3378,3581,3631,3757,3774,4011,
%U A262154 4161,4445,4551,5127,6002,6321,6722,7311,7547,8651,10044,10101,10637,11111,11762,12464,12831,12885,13141,13201,15461,16084,16451
%N A262154 Pseudoprimes to base 9, written in base 9.
%H A262154 Amiram Eldar, <a href="/A262154/b262154.txt">Table of n, a(n) for n = 1..10000</a>
%F A262154 a(n) = A007095(A020138(n)).
%t A262154 base = 9; t = {}; n = 1;
%t A262154 While[Length[t] < 80, n++;
%t A262154 If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
%t A262154 AppendTo[t, FromDigits@IntegerDigits[n, 9]]]]; t
%o A262154 (PARI) lista(nn, b=9) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ _Michel Marcus_, Sep 30 2015
%Y A262154 Cf. A007095 (numbers in base 9), A020138 (pseudoprimes to base 9).
%Y A262154 Cf. A258189, A262101, A262102, A262103, A262104, A262105.
%K A262154 nonn,base
%O A262154 1,1
%A A262154 _Abdul Gaffar Khan_, Sep 13 2015