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 A073700 a(1) = 1, a(n) = Floor[(Sum of composite numbers up to n)/(Sum of primes up to n)]. 0
 1, 0, 0, 0, 0, 1, 0, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 2, 2, 3, 3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,10 COMMENTS Though the sequence is not monotonically increasing the average value increases and a derived sequence could be the smallest value of k for which a(k) = n. Note 1 is neither composite nor prime. LINKS EXAMPLE a(10) = Floor[ {4+6+8+9+10}/{2+3+5+7)] =2. MAPLE a := 0:b := 0:for i from 2 to 300 do if isprime(i) then a := a+i: else b := b+i:fi: c[i] := floor(b/a):od:c[1] := 1:seq(c[j], j=1..300); MATHEMATICA Module[{nn=110, pr, comp}, pr=Prime[Range[PrimePi[nn]]]; comp=Complement[Range[ 2, nn], pr]; Join[{1}, Table[Floor[Total[Select[comp, #<=n&]]/Total[Select[pr, #<=n&]]], {n, 2, nn}]]] (* Harvey P. Dale, Feb 22 2013 *) Join[{1}, Table[t1 = Select[x = Range[n], PrimeQ]; Floor[Divide @@ Plus @@@ {Rest[Complement[x, t1]], t1}], {n, 2, 105}]] (* Jayanta Basu, Jul 07 2013 *) CROSSREFS Sequence in context: A204897 A262618 A107577 * A226957 A108775 A300826 Adjacent sequences:  A073697 A073698 A073699 * A073701 A073702 A073703 KEYWORD nonn AUTHOR Amarnath Murthy, Aug 12 2002 EXTENSIONS More terms from Sascha Kurz, Aug 15 2002 STATUS approved

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Last modified October 21 20:44 EDT 2019. Contains 328315 sequences. (Running on oeis4.)