cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A100765 Numbers for which the values of the Moebius function (A008683) and the Mertens function (A002321) are both -1.

Original entry on oeis.org

3, 41, 59, 66, 102, 151, 165, 167, 233, 239, 255, 354, 357, 359, 367, 402, 406, 409, 421, 426, 429, 609, 638, 782, 786, 797, 826, 854, 885, 887, 890, 894, 897, 907, 911, 1015, 1019, 1221, 1259, 1281, 1283, 1298, 1301, 1303, 1307, 1319, 1327, 1493, 1526, 1533
Offset: 1

Views

Author

Alonso del Arte, Jan 03 2005

Keywords

Comments

This sequence is a subsequence of A100306, Numbers for which the values of the Moebius function and the Mertens function agree.

Examples

			102 is in the sequence because it is a sphenic number (exactly 3 distinct prime factors, A007304) number, so the Mobius function yields -1 and the sum of that value and the previous Mobius values (the Mertens function) is also -1.
		

Crossrefs

Programs

  • Mathematica
    (* If not already defined *) If[Names["Mertens"] == {}, Mertens[x_] := Plus @@ MoebiusMu[Range[1, x]]]; Select[Range[2500], MoebiusMu[ # ] == -1 && Mertens[ # ] == -1 &]

Extensions

Offset corrected by Donovan Johnson, Jun 19 2012