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A073322
a(n)=A073259[A002808(n)] and a(0)=3; Length of FixedPointList started with n-th nonprime and leading to corresponding composite number= c[c(n)].
2
3, 4, 3, 3, 4, 4, 4, 4, 3, 3, 4, 4, 3, 3, 4, 4, 3, 4, 4, 4, 4, 4, 3, 3, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 4, 5, 4, 4, 3, 4, 4, 5, 4, 4, 3, 4, 4, 4, 3, 3, 4, 4, 4, 5, 4, 4, 5, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, 5, 4, 4, 4, 5, 4, 4, 3, 3, 3, 4, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 4, 5, 4, 4, 4, 5, 4, 4, 4, 5, 4
OFFSET
0,1
FORMULA
See Program.
EXAMPLE
list to n=0 corresponding to c[0]=1: {1,2,3,4} started with first nonprime ended with first composite; n=10: composite[10]=18, a(10)=length[{16,26,28}]=3.
MATHEMATICA
c[x_] := FixedPoint[x+c[ # ]+1&, x] lfp[x_] := Length[FixedPointList[x+c[ # ]+1&, x]]-1 Table[lfp[c[w]]-1, {w, 1, 128}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 29 2002
STATUS
approved