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Pseudoprimes to base 4, written in base 4.
7

%I #35 Jul 25 2021 02:40:04

%S 33,1111,1123,11111,12303,13003,20301,22011,22333,101101,103133,

%T 103313,111223,120231,122133,123001,131203,131301,133333,200113,

%U 212201,222031,230011,300331,303031,310213,321203,333001,1010101,1010103,1021021,1022323,1023323,1111111,1112233,1213021,1213303,1330111,2002001,2010201,2013313,2023033,2031211,2032223

%N Pseudoprimes to base 4, written in base 4.

%H Amiram Eldar, <a href="/A262101/b262101.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A007090(A020136(n)).

%t BaseForm[Select[Range[4096], Not[PrimeQ[#]] && PowerMod[4, # - 1, #] == 1 &], 4]

%o (PARI) lista(nn, b=4) = {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. A007090 (numbers in base 4), A020136 (pseudoprimes to base 4).

%Y Cf. A258189, A262102, A262103, A262104, A262105, A262154.

%K nonn,base

%O 1,1

%A _Abdul Gaffar Khan_, Sep 11 2015