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)].

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

Author

Labos Elemer, Jul 29 2002

Keywords

• nonn

Examples

			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.
		

Crossrefs

Cf. A002808, A073259, A073260.

Programs

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}]

Formula

See Program.