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.

A280446 Like A065759 but where f(n) = 2*n.

Original entry on oeis.org

5848, 6884, 58480, 68840, 394062, 584800, 688400, 3940620, 5848000, 6884000, 39406200, 58480000, 68840000
Offset: 1

Views

Author

Paolo P. Lava, Jan 03 2017

Keywords

Comments

Numbers of the form 5848*10^k, 6884*10^k, 394062*10^k, with k>=0, belong to the sequence.

Examples

			5848 = concat(5*848) = concat(58*48) = concat(584*8) and (5*848 + 58*48 + 584*8) = 11696 = 2*5848.
		

Crossrefs

Programs

  • Maple
    P:=proc(q) local a,k,n; for n from 1 to q do a:=0;
    for k from 1 to ilog10(n) do a:=a+(n mod 10^k)*trunc(n/10^k); od;
    if a/n=2 then print(n); fi; od; end: P(10^9);
  • Mathematica
    Select[Range[10^6], Function[n, Module[{a = {}, e = IntegerLength@ n - 1, k}, Do[AppendTo[a, # (n - #*10^(e - k)) &@ Floor[n/10^(e - k)]], {k, 0, e - 1}]; Total@ a] == 2 n]] (* Michael De Vlieger, Jan 04 2017 *)