A087882 a(n) = Prime[Abs[n-Prime[n-1]]] + PrimePi[ n- PrimePi[n-2]]

4, 5, 13, 15, 26, 32, 44, 65, 71, 93, 107, 111, 131, 156, 184, 186, 217, 235, 239, 269, 283, 317, 360, 380, 387, 405, 409, 429, 507, 529, 572, 578, 626, 628, 662, 692, 718, 753, 783, 797, 864, 868, 888, 892, 978, 1044, 1062, 1072, 1099, 1121, 1129, 1205

Offset

4,1

Comments

A prime based function based on A005185 as a pattern in a reinversion sequence.

Links

Table of n, a(n) for n=4..55.

Mathematica

prid[n_Integer?Positive] := prid[n] =Prime[Abs[n-Prime[n-1]]] + PrimePi[ n- PrimePi[n-2]] prid[1] = prid[2] = 1 digits=256 a=Table[prid[n], {n, 4, digits+4}]

Crossrefs

Cf. A005185.

Sequence in context: A227897 A156638 A098868 * A338544 A191196 A191136

Adjacent sequences: A087879 A087880 A087881 * A087883 A087884 A087885

Keyword

nonn

Author

Roger L. Bagula, Oct 12 2003

Status

approved