A094222 - OEIS

%I #15 Mar 01 2023 08:11:23

%S 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 42,45,47,48,50,52,54,56,58,60,63,65,67,68,70,73,74,76,78,81,82,84,87,

%U 89,90,93,95,97,98,100,102,105,108,110,113,114,117,119,121,122,124

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

%H G. C. Greubel, <a href="/A094222/b094222.txt">Table of n, a(n) for n = 1..5000</a>

%p A094222 := proc(n)

%p     option remember;

%p     if n <= 2 then

%p         n;

%p     else

%p         procname(n-1)+A001221(procname(n-1)) ;

%p     end if;

%p end proc:

%p seq(A094222(n),n=1..30) ; # _R. J. Mathar_, Jul 09 2016

%t 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 Cf. A001221, A160649.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, May 28 2004