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.

A342143 Take a(n), sort its digits into ascending order, divide the larger of the two numbers by the smaller and keep only the remainder: this remainder is present in a(n) as a substring of its digits.

Original entry on oeis.org

10, 20, 30, 40, 50, 52, 60, 70, 80, 90, 98, 100, 105, 106, 108, 110, 120, 130, 140, 150, 160, 170, 180, 186, 190, 198, 200, 205, 220, 230, 240, 250, 251, 260, 270, 274, 280, 290, 298, 300, 302, 330, 340, 350, 360, 370, 380, 390, 398, 400, 405, 410, 440, 450, 460, 470, 480, 490, 498, 500, 502, 510, 511
Offset: 1

Views

Author

Eric Angelini and Carole Dubois, Mar 01 2021

Keywords

Comments

In sorting a number, leading zeros are erased.
This is the lexicographically earliest sequence of distinct positive terms with this property.

Examples

			a(1) = 10, which sorted is 1 (leading zeros are erased); 10/1 leaves a remainder 0, which is present in a(1);
a(2) = 20, which sorted is 2 (leading zeros are erased); 20/2 leaves a remainder 0, which is present in a(2);
...
a(6) = 52, which sorted is 25; 52/25 leaves a remainder 2, which is present in a(6); etc.
		

Crossrefs

Cf. A090053.

Programs

  • Mathematica
    lst={};k=1;Do[While[!StringContainsQ[ToString@k,ToString@Mod[#2,#]&@@(Sort@{k,FromDigits@Sort@IntegerDigits@k})],k++];AppendTo[lst,k];k++,{n,62}];lst (* Giorgos Kalogeropoulos, May 08 2022 *)