A073260 Length of FixedPointList leading to value of [10^n]-th composite number.

4, 4, 4, 5, 5, 6, 7, 7, 7, 8, 8, 9, 9

Offset

1,1

Comments

One plus the number of iterations necessary to reach the composite number using the formula in the program. - Robert G. Wilson v, Jul 23 2002

Links

Table of n, a(n) for n=1..13.

Formula

See program below.

Example

n=10^11: the list= {100000000000, 104118054814, 104280509328, 104286914053, 104287166025, 104287176027, 104287176414, 104287176419}, its length including initial term is 8, so a(11)=8.

Mathematica

Table[Length[FixedPointList[10^w+PrimePi[ # ]+1&, 10^w]]-1, {w, 1, 11}]

Crossrefs

Cf. A064814, A065857, A002808, A073255-A073264.

Sequence in context: A369339 A368868 A134992 * A350459 A036854 A036858

Adjacent sequences: A073257 A073258 A073259 * A073261 A073262 A073263

Keyword

nonn,more

Author

Labos Elemer, Jul 22 2002

Extensions

More terms from Robert G. Wilson v, Jul 23 2002

Status

approved