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A094222 a(n+1) = a(n) + (number of distinct prime factors of a(n)) for n>1; a(1)=1, a(2)=2.

%I A094222 #15 Mar 01 2023 08:11:23
%S A094222 1,2,3,4,5,6,8,9,10,12,14,16,17,18,20,22,24,26,28,30,33,35,37,38,40,
%T A094222 42,45,47,48,50,52,54,56,58,60,63,65,67,68,70,73,74,76,78,81,82,84,87,
%U A094222 89,90,93,95,97,98,100,102,105,108,110,113,114,117,119,121,122,124
%N A094222 a(n+1) = a(n) + (number of distinct prime factors of a(n)) for n>1; a(1)=1, a(2)=2.
%H A094222 G. C. Greubel, <a href="/A094222/b094222.txt">Table of n, a(n) for n = 1..5000</a>
%p A094222 A094222 := proc(n)
%p A094222     option remember;
%p A094222     if n <= 2 then
%p A094222         n;
%p A094222     else
%p A094222         procname(n-1)+A001221(procname(n-1)) ;
%p A094222     end if;
%p A094222 end proc:
%p A094222 seq(A094222(n),n=1..30) ; # _R. J. Mathar_, Jul 09 2016
%t A094222 a[1] = 1; a[2] = 2; a[n_] := a[n] = a[n-1] + PrimeNu[a[n-1]]; Array[a, 66] (* _Jean-François Alcover_, Sep 13 2016 *)
%Y A094222 Cf. A001221, A160649.
%K A094222 nonn
%O A094222 1,2
%A A094222 _Reinhard Zumkeller_, May 28 2004