[seqfan] Re: zig-zag pseudoprimes

[peter.luschny]

vs> Nevertheless, I did not understand if you really obtained that,
vs> e.g., A000111(561)==1(mod 561)?

RJM> Yes. I naively trusted that the following Maple implementation works
RJM> on my computer (one of the two branches of your problem in comments):
RJM> A000111 := proc(n)
RJM>        2^n*abs( euler(n,1/2)+euler(n,1)) ;
RJM> end proc:
RJM> [...]

And this shows that the Guy Steele sequence GS(4,2) is involved.
This might be of interest for Vladimir as he commented on other
Guy Steele sequences before.

Peter