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%I #11 Apr 17 2018 23:06:17
%S 1,2,4,5,8,11,16,17,25,29,32,37,49,53,64,67,81,83,121,127,128,131,169,
%T 173,243,251,256,257,289,293,343,347,361,367,512,521,529,541,625,631,
%U 729,733,841,853,961,967,1024,1031,1331,1361,1369,1373,1681,1693,1849
%N a(0)=1. a(2n-1) = smallest prime > a(2n-2). a(2n) = smallest proper prime power > a(2n-1).
%C Alternating between elements of A000040 and A025475. - _R. J. Mathar_, Mar 09 2010
%p From _R. J. Mathar_, Mar 09 2010: (Start)
%p isA025475 := proc(n) pdec := ifactors(n)[2] ; if nops(pdec) = 1 then return ( op(2,op(1,pdec)) > 1 ); else false; end if; end proc:
%p A175106 := proc(n) option remember; local a; if n = 0 then 1; else if type(n,'odd') then nextprime(procname(n-1)) ; else for a from procname(n-1)+1 do if isA025475(a) then return a ; end if; end do ; end if; end if; end proc:
%p seq(A175106(n),n=0..80) ; (End)
%Y Cf. A246547.
%K nonn
%O 0,2
%A _Leroy Quet_, Feb 11 2010
%E Extended by _Ray Chandler_, Mar 11 2010
%E More terms from _R. J. Mathar_, Mar 09 2010
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