A087876 a[n] =PrimePi[PrimePi[n-2]] + a[n - a[n-2]]

1, 1, 1, 1, 2, 3, 4, 4, 4, 5, 6, 6, 7, 7, 7, 7, 8, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 12, 13, 13, 13, 14, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 17, 18, 18, 18, 19, 19, 19, 19, 20, 21, 21, 21, 21, 21, 21, 21, 22, 22, 23, 23, 23, 23, 23, 24, 25, 25, 26, 26, 26, 26, 27, 27, 27

Offset

1,5

Comments

A PrimePi reinversion based on Mallows A005229 as the pattern sequence.

Links

Table of n, a(n) for n=1..75.

Mathematica

mrid[n_Integer?Positive] := mrid[n] =PrimePi[PrimePi[n-2]] + mrid[n - mrid[n-2]] mrid[1] = mrid[2] = 1 digits=256 a=Table[mrid[n], {n, 1, digits}]

Crossrefs

Cf. A005229.

Sequence in context: A167991 A173073 A073425 * A006158 A340203 A135414

Adjacent sequences: A087873 A087874 A087875 * A087877 A087878 A087879

Keyword

nonn

Author

Roger L. Bagula, Oct 11 2003

Status

approved