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.

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A192544 Bases b such that all integers m having the commuting property r(m)^2 = r(m^2), where r is cyclic replacement of digits d->(d+1) mod b, are of the form m = (b/2 - 1)*(b^k - 1)/(b - 1) + 1 for k >= 1.

Original entry on oeis.org

8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 148, 152, 156, 160, 164, 168, 172, 176, 180, 184, 188, 192, 196, 200, 204, 208, 212, 216, 220, 224, 228, 232, 236, 240, 244, 248, 252, 256, 260, 264
Offset: 1

Views

Author

Walter Kehowski, Jul 04 2011

Keywords

Comments

The bases b form the arithmetic sequence 8+4*k, k>=0, so b/2 is necessarily even. The bases b=2 and b=4 have b/2 as the only number with the commuting property. No odd base b has the commuting property.

Examples

			In base 8, the numbers with the commuting property are 4, 34, 334, 3334, 33334, 333334 etc, given by the formula 3*(8^k - 1)/7 + 1.
		

Crossrefs

Except for initial terms, same as A008586 and A124354.

Programs

  • Mathematica
    a[n_] := 4*(n + 1); Table[a[n], {n, 1, 65}] (* Robert P. P. McKone, Aug 25 2023 *)

Formula

From Chai Wah Wu, Dec 29 2021: (Start)
a(n) = 2*a(n-1) - a(n-2) for n > 2.
G.f.: x*(8 - 4*x)/(x - 1)^2. (End)

Extensions

More terms from Chai Wah Wu, Dec 29 2021
Edited by Max Alekseyev, Aug 24 2023

A059557 Beatty sequence for 1 + gamma^2, (gamma is the Euler-Mascheroni constant A001620).

Original entry on oeis.org

1, 2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 25, 26, 27, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, 59, 61, 62, 63, 65, 66, 67, 69, 70, 71, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89, 90, 91, 93, 94
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Crossrefs

Beatty complement is A059558.

Programs

  • Magma
    R:=RealField(100); [Floor((1+EulerGamma(R)^2)*n): n in [1..100]]; // G. C. Greubel, Aug 27 2018
  • Mathematica
    Table[Floor[(1 + EulerGamma^2)*n], {n,1,100}] (* G. C. Greubel, Aug 27 2018 *)
  • PARI
    { default(realprecision, 100); b=1 + Euler^2; for (n = 1, 2000, write("b059557.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009
    

Formula

a(n) = A042968(n-1), 1<=n<2146. - R. J. Mathar, Oct 05 2008
Showing 1-2 of 2 results.