A073259 Number of iterations of f(n,k) = n+pi(k)+1 starting from f(n,n) until a fixed point is reached.

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

Offset

1,1

Comments

Original name: Length of FixedPointList leading to value of n-th composite number.

Links

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

Formula

See program below.

Example

n=1000000:the list={1000000,1078499,1084157,1084577,1084604,1084605}, its length including initial term is 6, while composite[1000000]=1084605.

Mathematica

Table[Length[FixedPointList[w+PrimePi[ # ]+1&, w]]-1, {w, 1, 128}]

Crossrefs

Cf. A000720, A064814, A002808, A073255-A073264.

Sequence in context: A117499 A063570 A023977 * A174987 A214926 A268368

Adjacent sequences: A073256 A073257 A073258 * A073260 A073261 A073262

Keyword

nonn

Author

Labos Elemer, Jul 22 2002

Extensions

Name clarified by Sean A. Irvine, Nov 21 2024

Status

approved