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 A256346 #7 Mar 10 2021 01:19:14 %S A256346 10,17,18,20,30,34,36,40,49,50,51,54,55,60,68,70,72,73,80,85,90,98,99, %T A256346 100,102,108,110,115,118,119,120,126,136,140,144,145,146,147,150,153, %U A256346 160,165,170,180,187,190,194,196,198,199,200,204,207,210,211,216,219,220,230,236,238,240,245,250 %N A256346 Moduli n for which A248218(n) = 6. %C A256346 If x is a member of this sequence, and y is a member of this sequence or A248219 or A256342 or A256343, then LCM(x,y) is a member of this sequence. - _Robert Israel_, Mar 09 2021 %H A256346 Robert Israel, <a href="/A256346/b256346.txt">Table of n, a(n) for n = 1..10000</a> %p A256346 filter:= proc(n) local x, k, R,p; %p A256346 x:= 0; R[0]:= 0; %p A256346 for k from 1 do %p A256346 x:= x^2+1 mod n; %p A256346 if assigned(R[x]) then return evalb(k-R[x] = 6) %p A256346 else R[x]:= k %p A256346 fi %p A256346 od; %p A256346 end proc: %p A256346 select(filter, [$1..1000]); # _Robert Israel_, Mar 09 2021 %o A256346 (PARI) for(i=1,250,A248218(i)==6&&print1(i",")) %Y A256346 Cf. A248218, A248219, A256342 - A256349, A003095, A247981. %K A256346 nonn %O A256346 1,1 %A A256346 _M. F. Hasler_, Mar 25 2015