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%I #5 Oct 15 2017 01:05:12
%S 3277,838861,13421773,3435973837,54975581389,14073748835533,
%T 57646075230342349,922337203685477581,3777893186295716170957,
%U 967140655691703339764941,15474250491067253436239053,3961408125713216879677197517,16225927682921336339157801028813
%N Numbers of the form (2^(2p) + 1)/5, where p is a prime > 5.
%C Rotkiewicz proved that all the terms in this sequence are Fermat pseudoprimes to base 2 (A001567).
%H Andrzej Rotkiewicz, <a href="http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.bwnjournal-article-cmv12i1p69bwm">Sur les formules donnant des nombres pseudopremiers</a>, Colloquium Mathematicae, Vol. 12, No. 1 (1964), pp. 69-72.
%e 3277 = (2^(2*7) + 1)/5 is the first term, corresponding to the prime p = 7.
%t p = Select[Range[7,60], PrimeQ]; (2^(2p) + 1)/5
%Y Cf. A001567, A210454.
%K nonn
%O 1,1
%A _Amiram Eldar_, Oct 13 2017
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