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.

Showing 1-2 of 2 results.

A341059 Numbers k such that A340179(k) is a square.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 11, 12, 15, 17, 27, 48, 92, 6219, 24310
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Feb 04 2021

Keywords

Examples

			a(6) = 8 is a term because A340179(8) = 4 = 2^2.
		

Crossrefs

Programs

  • Maple
    f:= proc(n) local C, s, c;
      C:=select(t -> igcd(t, n) = 1, [$1..n-1]);
      s:= convert(C, `+`);
      add(s mod c, c = C)
    end proc:
    select(t -> issqr(f(t)), [$1..7000]);

A341060 Numbers k such that A340179(k) is a multiple of k.

Original entry on oeis.org

1, 2, 10, 16, 30, 74, 81, 97, 489, 525, 607, 1861, 4439, 26051
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Feb 04 2021

Keywords

Examples

			a(4) = 16 is a term because A340179(16) = 32 = 2*16.
		

Crossrefs

Programs

  • Maple
    f:= proc(n) local C, s, c;
      C:=select(t -> igcd(t, n) = 1, [$1..n-1]);
      s:= convert(C, `+`);
      add(s mod c, c = C)
    end proc:
    select(t -> f(t) mod t = 0, [$1..5000]);
  • Mathematica
    A340179[n_] := Total@Mod[#2, #1]& @@ {#, Total@#}& @ Select[Range[n], GCD[#, n] == 1&];
    Reap[For[k = 1, k <= 80000, k++, If[Divisible[A340179[k], k], Print[k]; Sow[k]]]][[2, 1]] (* Jean-François Alcover, May 16 2023, after Michael De Vlieger in A340179 *)
Showing 1-2 of 2 results.