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%I #11 Jun 19 2019 14:13:06
%S 0,1,3,4,6,7,10,11,12,13,16,17,20,21,23,25,27,28,31,32,34,36,39,40,42,
%T 43,45,46,49,50,54,55,56,58,60,62,65,66,68,70,73,74,78,79,81,83,86,87,
%U 89,90,92,94,97,98,100,102,104,106,109,110,114,115,117,119,120,122
%N a(n) = Sum_{p prime and p<=n} ceiling(n/p).
%C a(n) = A013939(n) + A048865(n).
%H Robert Israel, <a href="/A092494/b092494.txt">Table of n, a(n) for n = 1..10000</a>
%p N:= 100: # for a(1)..a(N)
%p V:= Vector(N):
%p p:= 0:
%p do
%p p:= nextprime(p);
%p if p > N then break fi;
%p V[p]:= V[p]+1;
%p for k from 2 to floor(N/p) do
%p V[(k-1)*p+1 .. k*p]:= V[(k-1)*p+1 .. k*p] +~ k;
%p od;
%p if (k-1)*p+1<=N then V[(k-1)*p+1..N]:= V[(k-1)*p+1..N]+~ k fi
%p od:
%p convert(V,list); # _Robert Israel_, Jun 19 2019
%o (PARI) a(n) = sum(k=1, n, isprime(k)*ceil(n/k)); \\ _Michel Marcus_, Jun 19 2019
%Y Cf. A006590.
%K nonn
%O 1,3
%A _Reinhard Zumkeller_, Apr 05 2004
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