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 A293626 #5 Oct 15 2017 01:05:12 %S A293626 3277,838861,13421773,3435973837,54975581389,14073748835533, %T A293626 57646075230342349,922337203685477581,3777893186295716170957, %U A293626 967140655691703339764941,15474250491067253436239053,3961408125713216879677197517,16225927682921336339157801028813 %N A293626 Numbers of the form (2^(2p) + 1)/5, where p is a prime > 5. %C A293626 Rotkiewicz proved that all the terms in this sequence are Fermat pseudoprimes to base 2 (A001567). %H A293626 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 A293626 3277 = (2^(2*7) + 1)/5 is the first term, corresponding to the prime p = 7. %t A293626 p = Select[Range[7,60], PrimeQ]; (2^(2p) + 1)/5 %Y A293626 Cf. A001567, A210454. %K A293626 nonn %O A293626 1,1 %A A293626 _Amiram Eldar_, Oct 13 2017