A073321 a(n)=A073259[A000040(n)]; Length of FixedPointList started with n-th prime and leading to corresponding composite number.

4, 4, 3, 4, 4, 3, 3, 4, 3, 5, 3, 4, 3, 5, 3, 4, 4, 4, 4, 3, 4, 5, 5, 3, 4, 4, 3, 4, 3, 3, 4, 4, 4, 5, 5, 4, 4, 3, 4, 3, 5, 4, 4, 4, 4, 4, 4, 5, 4, 4, 4, 4, 3, 5, 4, 3, 5, 4, 3, 4, 5, 4, 5, 4, 4, 4, 4, 4, 4, 5, 4, 4, 4, 6, 4, 4, 4, 5, 4, 4, 4, 4, 4, 4, 3, 4, 4, 4, 4, 4, 5, 4, 4, 6, 4, 4, 4, 4, 4, 5, 4, 4, 4, 4, 4

Offset: 1

Author

Labos Elemer, Jul 29 2002

Keywords

• nonn

Examples

			a=10,p(10)=29, list={29,40,42,43,44}.
		

Crossrefs

Cf. A002808, A073259.

Programs

Mathematica

lfp[x_] := Length[FixedPointList[x+PrimePi[ # ]+1&, x]]-1 Table[lfp[Prime[w]]-1, {w, 1, 128}]

Formula

See Program.