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.

Showing 1-2 of 2 results.

A033766 Number of prime divisors (counted without multiplicity) of A138613(n).

Original entry on oeis.org

1, 1, 2, 3, 6, 8, 11, 20, 29, 47, 78, 129, 230, 400, 710, 1221
Offset: 1

Views

Author

N. J. A. Sloane, Sep 20 2008

Keywords

Comments

The old entry with this sequence number was a duplicate of A035162.

Crossrefs

Cf. A138613, A079488, A001221.

Programs

  • Mathematica
    PrimeNu[NestList[DivisorSigma[2,#]&,2,12]] (* Harvey P. Dale, Aug 19 2017 *)

Extensions

a(10)-a(12) from Donovan Johnson, Nov 17 2008
a(13)-a(16) from Daniel Suteu, Dec 11 2019

A079488 Number of prime divisors (counted with multiplicity) of A138613(n).

Original entry on oeis.org

1, 1, 2, 4, 7, 14, 23, 36, 72, 106, 172, 314, 542, 1008, 1766, 3151
Offset: 1

Views

Author

N. J. A. Sloane, Sep 20 2008

Keywords

Comments

The old entry with this sequence number was a duplicate of A052553.

Crossrefs

Cf. A138613, A033766, A001222.

Formula

a(n) = A001222(A138613(n)). - R. J. Mathar, Sep 21 2008

Extensions

a(10) from R. J. Mathar, Sep 21 2008
a(11)-a(12) from Donovan Johnson, Dec 19 2008
a(13)-a(16) from Daniel Suteu, Dec 11 2019
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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