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

1,1

Links

Table of n, a(n) for n=1..105.

Formula

See Program.

Example

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

Mathematica

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

Crossrefs

Cf. A002808, A073259.

Sequence in context: A307836 A106147 A202393 * A055620 A072420 A258075

Adjacent sequences: A073318 A073319 A073320 * A073322 A073323 A073324

Keyword

nonn

Author

Labos Elemer, Jul 29 2002

Status

approved