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%I #8 Oct 15 2013 22:31:24
%S 0,0,0,1,2,6,17,41,94,215,470,1004,2126,4449,9278,19177,39388,80698,
%T 164808,335809,683117,1387415,2813664,5700228,11536241,23324624,
%U 47122764,95134678,191937316,387024829,780018815,1571331010
%N Number of even nontotients not exceeding 2^n.
%e n = 6: a(6) = 6 because the even nontotients not exceeding 64 are {14,26,34,38,50,62}.
%t a = Table[0, {2^26}]; Do[ b = EulerPhi[n]; If[ EvenQ[b] && b < 2^27, a[[b/2]]++ ], {n, 3, 10^9}]; c = 0; k = 1; Do[ While[k <= 2^n, If[ a[[k]] == 0, c++ ]; k++ ]; Print[c], {n, 1, 17}]
%Y Number of terms in A005277 <= 2^n.
%K nonn,hard
%O 1,5
%A _Labos Elemer_, Jun 13 2002
%E Edited and extended by _Robert G. Wilson v_, Jul 15 2002
%E a(27)-a(32) from _Donovan Johnson_, Jun 03 2013
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