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 1-3 of 3 results.

A277568 Numbers k such that k/6^m == 2 (mod 6), where 6^m is the greatest power of 6 that divides k.

Original entry on oeis.org

2, 8, 12, 14, 20, 26, 32, 38, 44, 48, 50, 56, 62, 68, 72, 74, 80, 84, 86, 92, 98, 104, 110, 116, 120, 122, 128, 134, 140, 146, 152, 156, 158, 164, 170, 176, 182, 188, 192, 194, 200, 206, 212, 218, 224, 228, 230, 236, 242, 248, 254, 260, 264, 266, 272, 278
Offset: 1

Views

Author

Clark Kimberling, Nov 01 2016

Keywords

Comments

Positions of 2 in A277544.
Numbers having 2 as rightmost nonzero digit in base 6. This is one sequence in a 5-way splitting of the positive integers; the other four are indicated in the Mathematica program. Every term is even; see A277572.

Links

Crossrefs

Cf. A277544, A277567, A277569, A277572.

Programs

  • Mathematica
    z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
p[b_, d_] := Flatten[Position[a[b], d]]
p[6, 1] (* A277567 *)
p[6, 2] (* A277568 *)
p[6, 3] (* A277569 *)
p[6, 4] (* A277570 *)
p[6, 5] (* A277571 *)
  • PARI
    is(n)=(n/6^valuation(n,6))%6==2 \\ Charles R Greathouse IV, Nov 03 2016

Formula

a(n) = 5n + O(log n). - Charles R Greathouse IV, Nov 03 2016

A277573 a(n) = (1/3)*A277569(n).

Original entry on oeis.org

1, 3, 5, 6, 7, 9, 11, 13, 15, 17, 18, 19, 21, 23, 25, 27, 29, 30, 31, 33, 35, 36, 37, 39, 41, 42, 43, 45, 47, 49, 51, 53, 54, 55, 57, 59, 61, 63, 65, 66, 67, 69, 71, 73, 75, 77, 78, 79, 81, 83, 85, 87, 89, 90, 91, 93, 95, 97, 99, 101, 102, 103, 105, 107, 108
Offset: 1

Views

Author

Clark Kimberling, Nov 01 2016

Keywords

Comments

From Amiram Eldar, Jan 16 2022: (Start)
Numbers whose 3-adic valuation is not smaller than their 2-adic valuation.
The asymptotic density of this sequence is 3/5. (End)

Links

Crossrefs

Cf. A007814, A007949.
Cf. A277568, A277569, A277572, A277574.

Programs

  • Mathematica
    z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
p[b_, d_] := Flatten[Position[a[b], d]]
p[6, 3]/3
(* second program *)
Select[Range[200], IntegerExponent[#, 3] >= IntegerExponent[#, 2] &] (* Amiram Eldar, Jan 16 2022 *)

A277574 (1/2)*A277570.

Original entry on oeis.org

2, 5, 8, 11, 12, 14, 17, 20, 23, 26, 29, 30, 32, 35, 38, 41, 44, 47, 48, 50, 53, 56, 59, 62, 65, 66, 68, 71, 72, 74, 77, 80, 83, 84, 86, 89, 92, 95, 98, 101, 102, 104, 107, 110, 113, 116, 119, 120, 122, 125, 128, 131, 134, 137, 138, 140, 143, 146, 149, 152
Offset: 1

Views

Author

Clark Kimberling, Nov 01 2016

Keywords

Links

Crossrefs

Cf. A277568, A277572, A277573.

Programs

  • Mathematica
    z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
p[b_, d_] := Flatten[Position[a[b], d]]
p[6, 2]/2 (* A277572 *)
p[6, 3]/3 (* A277573 *)
p[6, 4]/2 (* A277574 *)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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