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.

A180477 Numbers n such that r*n/k is an integer. n=(x_1 x_2 ... x_r) where x_i are digits of n, k = x_1 + x_2 + ... + x_r.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18, 20, 21, 22, 24, 27, 30, 33, 36, 40, 42, 44, 45, 48, 50, 51, 54, 55, 60, 63, 66, 70, 72, 77, 80, 81, 84, 88, 90, 99, 100, 102, 108, 110, 111, 112, 114, 117, 120, 126, 132
Offset: 1

Views

Author

Ctibor O. Zizka, Sep 07 2010

Keywords

Comments

A005349 is a subsequence of this sequence.
n * A055642(a(n)) mod A007953(a(n)) = 0. - Reinhard Zumkeller, Oct 27 2015

Examples

			n=126, r=3, 3*126/(1+2+6)=42, so 126 belongs to this sequence.
		

Crossrefs

Cf. A005349.
Cf. A007953, A055642, subsequence of A263808.

Programs

  • Haskell
    a180477 n = a180477_list !! (n-1)
    a180477_list = filter (\x -> mod (x * a055642 x) (a007953 x) == 0) [1..]
    -- Reinhard Zumkeller, Oct 27 2015