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