A103991 Reduced denominators of the hypercube line-picking integrand sqrt(Pi)*I(n,0).

3, 5, 21, 9, 11, 39, 15, 17, 57, 21, 23, 75, 27, 29, 93, 33, 35, 111, 39, 41, 129, 45, 47, 147, 51, 53, 165, 57, 59, 183, 63, 65, 201, 69, 71, 219, 75, 77, 237, 81, 83, 255, 87, 89, 273, 93, 95, 291, 99, 101, 309, 105, 107, 327, 111, 113, 345, 117, 119, 363

Offset

1,1

Comments

Sequence appears to be trisected into a(3n+1) = 6n-3 = A016945(n-1); a(3n+2) = 6n-1 = A016969(n-1); a(3n+3) = 18n+3. - Ralf Stephan, Nov 13 2010

Links

Table of n, a(n) for n=1..60.

Eric Weisstein's World of Mathematics, Hypercube Line Picking

Formula

Empirical g.f.: -x*(3*x^5-x^4-3*x^3-21*x^2-5*x-3) / ((x-1)^2*(x^2+x+1)^2). - Colin Barker, May 05 2014

Example

2/3, 6/5, 50/21, 38/9, 74/11, 386/39, 206/15, 310/17, 1334/57, 614/21, ...

Mathematica

Rest[CoefficientList[Series[-x*(3*x^5-x^4-3*x^3-21*x^2-5*x-3) / ((x-1)^2*(x^2+x+1)^2), {x, 0, 60}], x]] (* James C. McMahon, Jan 18 2024 *)

Crossrefs

Cf. A103990.

Sequence in context: A256093 A066902 A007363 * A224994 A321768 A331395

Adjacent sequences: A103988 A103989 A103990 * A103992 A103993 A103994

Keyword

nonn,frac

Author

Eric W. Weisstein, Feb 23 2005

Extensions

a(21)-a(60) from James C. McMahon, Jan 18 2024

Status

approved