A122668 a(n) = d(n)_n where d() = A000005.

1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 9, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 48, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 62, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 74, 2, 4, 6, 6, 4, 8, 2, 80, 5, 4, 2, 86, 4, 4, 4, 8, 2, 92, 4, 6, 4, 4, 4, 98, 2, 6, 6, 9

Offset: 1

Author

N. J. A. Sloane, Sep 22 2006

Keywords

• nonn
• base

Comments

See A122618 for notation.

Examples

			From _Antti Karttunen_, Aug 24 2017: (Start)
For n = 48, A000005(48) = 10, in decimal "10". This read in base-48 is 1*(48^1) + 0*(48^0) = 48, thus a(48) = 48, which is the first time this sequence differs from A000005.
For n = 60, A000005(60) = 12, in decimal "12". This read in sexagesimal base is 1*(60^1) + 2*(60^0), thus a(60) = 62. (End)
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A122618, A122667.

Programs

Mathematica

a[n_]:=FromDigits[IntegerDigits[DivisorSigma[0,n]], n]; Array[a, 100] (* Stefano Spezia, May 03 2025 *)

PARI

A122618(n, d=digits(n)) = d*vectorv(#d, i, n^(#d-i)); \\ M. F. Hasler, Apr 22 2015
A122668(n) = A122618(n,digits(numdiv(n))); \\ Antti Karttunen, Aug 24 2017