login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A164661 Denominators of row sums of triangle of rationals A164658/A164659. Definite integral of Chebyshev polynomials of the first kind: Integral_{x=0..1} T(n,x). 7
1, 2, 3, 2, 15, 6, 35, 6, 63, 10, 99, 10, 143, 14, 195, 14, 255, 18, 323, 18, 399, 22, 483, 22, 575, 26, 675, 26, 783, 30, 899, 30, 1023, 34, 1155, 34, 1295, 38, 1443, 38, 1599, 42, 1763, 42, 1935, 46, 2115, 46, 2303, 50, 2499, 50, 2703, 54, 2915, 54, 3135, 58, 3363, 58, 3599 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The numerators are given in A164660.

See the W. Lang link under A164660 for a list of the first rationals.

LINKS

Table of n, a(n) for n=0..60.

Index entries for sequences related to Chebyshev polynomials.

FORMULA

a(n) = denominator(Sum_{m=1..n+1} IT(n,m)), n>=0, with IT(n,m):= A164658(n,m)/A164659(n,m) (coefficient triangle from the indefinite integral Integral_{x} T(n,x), n>=0, in lowest terms).

EXAMPLE

Rationals A164660(n)/a(n) = [1, 1/2, -1/3, -1/2, -1/15, 1/6, -1/35, -1/6, -1/63, 1/10, -1/99, ...].

CROSSREFS

Sequence in context: A205441 A181350 A174111 * A104507 A101033 A136454

Adjacent sequences:  A164658 A164659 A164660 * A164662 A164663 A164664

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang, Oct 16 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 27 10:28 EDT 2021. Contains 347689 sequences. (Running on oeis4.)