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.

A227157 Numbers k whose factorial base representation A007623(k) does not contain any nonleading zeros.

Original entry on oeis.org

1, 3, 5, 9, 11, 15, 17, 21, 23, 33, 35, 39, 41, 45, 47, 57, 59, 63, 65, 69, 71, 81, 83, 87, 89, 93, 95, 105, 107, 111, 113, 117, 119, 153, 155, 159, 161, 165, 167, 177, 179, 183, 185, 189, 191, 201, 203, 207, 209, 213, 215, 225, 227, 231, 233, 237, 239, 273
Offset: 1

Views

Author

Antti Karttunen, Jul 04 2013

Keywords

Comments

a(A003422(n)) = A007489(n).
a(A007489(n)) = (n+1)!-1 thus A007489(n) gives the number of terms less than (n+1)! in this sequence.
Equivalently, there are n! terms in the sequence with their magnitude in range n!..(n+1)!.
Also numbers k such that A304036(k) = 1 for k > 0. - Seiichi Manyama, May 06 2018

Crossrefs

The sequence gives all n for which A208575(n) is not zero. Complement of A227187. Subsets: A071156 (apart from zero), A231716, A231720.

Programs

  • Mathematica
    q[n_] := Module[{k = n, m = 2, c = 0, r}, While[{k, r} = QuotientRemainder[k, m]; k != 0 || r != 0, If[r == 0, c++]; m++]; c == 0]; Select[Range[300], q] (* Amiram Eldar, Jan 23 2024 *)