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.

A105607 Sylvester cyclotomic numbers for A002605.

Original entry on oeis.org

1, 2, 6, 8, 44, 10, 328, 56, 408, 76, 18272, 52, 136384, 568, 3856, 3104, 7598336, 424, 56714752, 2896, 215104, 31648, 3159738368, 3088, 536013824, 236224, 71910912, 161344, 1313964867584, 2320, 9807567290368, 9634304, 667730944, 13160704, 37860806656, 172864, 4078438577864704, 98232832, 37201186816, 9584896
Offset: 1

Views

Author

Paul Barry, Apr 15 2005

Keywords

Comments

Primitive parts of A002605.

Crossrefs

Programs

  • Mathematica
    f[n_] := FullSimplify[ Expand[ Times @@ ((1+Sqrt[3])-(1-Sqrt[3])*Exp[2Pi*I*Select[Range[n-1], GCD[ #, n] == 1 &]/n])]]; Table[ f[n], {n, 1, 32}] (* Robert G. Wilson v, Aug 02 2005 *)

Formula

a(n) = A002605(n)/A105606(n); a(n) = Product_{k=1..n-1, gcd(n, k)=1} (1+sqrt(3))-(1-sqrt(3))*exp(2*Pi*i*k/n), i = sqrt(-1). - Robert G. Wilson v, Aug 02 2005

Extensions

More terms from David Wasserman, May 06 2008

A105608 Sylvester dividends for A002605.

Original entry on oeis.org

1, 1, 1, 2, 1, 12, 1, 16, 6, 88, 1, 960, 1, 656, 264, 896, 1, 48960, 1, 53504, 1968, 36544, 1, 2795520, 44, 272768, 2448, 2980864, 1, 1547335680, 1, 2781184, 109632, 15196672, 14432, 8635760640, 1, 113429504, 818304, 8677064704, 1, 4808968273920, 1, 9252356096, 415337472, 6319476736, 1, 26795484119040, 328, 3584860454912
Offset: 1

Views

Author

Paul Barry, Apr 15 2005

Keywords

Crossrefs

Programs

  • Mathematica
    f[n_] := FullSimplify[ Expand[ Times @@ ((1+Sqrt[3])-(1-Sqrt[3])*Exp[2Pi*I*Select[Range[n-1], GCD[ #, n] > 1 &]/n])]]; Table[ f[n], {n, 1, 32}] (* Robert G. Wilson v, Aug 02 2005 *)

Formula

a(n) = A002605(n)/A105607(n); a(n) = Product_{k=1..n-1, gcd(n, k)>1} (1+sqrt(3))-(1-sqrt(3))*exp(2*Pi*i*k/n), i = sqrt(-1).

Extensions

More terms from David Wasserman, May 06 2008
Showing 1-2 of 2 results.