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A072415 a(1) = 2; a(n) = a(n-1)-th even nontotient number. 2

%I #11 Mar 13 2015 00:31:28

%S 2,26,182,878,3626,13508,46922,155156,494468,1529590,4615074,13633310,

%T 39548078,112918434,317920082,883996002

%N a(1) = 2; a(n) = a(n-1)-th even nontotient number.

%F a(3)=182 is the 26th = a(2)-th term in A005277.

%t a = Table[0, {10^6}]; Do[b = EulerPhi[n]/2; If[b < 10^6 + 1, a[[b]] = 1], {n, 1, 2 10^7}]; b = Select[ Range[10^6], a[[ # ]] == 0 &]; c = 1; Do[ Print[c]; c = 2b[[c]], {n, 0, 8}]

%Y Cf. A006508, A071255, A005277, A072416.

%K more,nonn

%O 1,1

%A _Labos Elemer_, Jun 17 2002

%E Edited by _Robert G. Wilson v_, Jun 20 2002

%E a(11)-a(16) from _Donovan Johnson_, Oct 29 2010

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Last modified May 7 18:53 EDT 2024. Contains 372313 sequences. (Running on oeis4.)