Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #4 Nov 22 2015 15:23:39
%S 509203,2554843,9203917,9545351,10645867,11942443,14608183,15627133,
%T 15811777,16413457,21013423,21465637,25792993,30622663,30932729,
%U 32126257,37996753,40672237,41641181,43099781,43773809,47775613,48400783,52518187,52992283
%N Prime Riesel numbers p that are not Mersenne primes such that 2*p is a noncototient.
%C Each of the numbers 2^k*a(n), where k >= 1, is a noncototient.
%H J. Browkin and A. Schinzel, <a href="http://matwbn.icm.edu.pl/ksiazki/cm/cm68/cm6817.pdf">On integers not of the form n - phi(n)</a>, Colloq. Math. 68 (1995), pp. 55-58.
%H A. Flammenkamp and F. Luca, <a href="http://matwbn.icm.edu.pl/ksiazki/cm/cm86/cm8616.pdf">Infinite families of noncototients</a>, Colloq. Math. 86 (2000), pp. 37-41.
%Y Cf. A005278, A182296.
%K nonn
%O 1,1
%A _Arkadiusz Wesolowski_, Oct 30 2015