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!)
A176727 Denominator of a-sequence for Sheffer triangle A060081. 4
1, 1, 3, 1, 15, 1, 21, 1, 45, 1, 33, 1, 1365, 1, 45, 1, 765, 1, 399, 1, 3465, 1, 1035, 1, 20475, 1, 189, 1, 435, 1, 7161, 1, 58905, 1, 315, 1, 959595, 1, 117, 1, 20295, 1, 148995, 1, 108675, 1, 14805, 1, 2436525, 1, 65637, 1, 78705, 1, 21945, 1, 24795, 1, 531, 1, 85180095, 1, 135135 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The numerator sequence is A176726.

For a- and z-sequences for Sheffer triangles see the W. Lang link under A006232.

LINKS

Table of n, a(n) for n=0..62.

W. Lang: Rationals A176726/A176727.

FORMULA

E.g.f. for rational a-sequence A176726/A176727: x/log(sqrt((1+x)/(1- x))).

EXAMPLE

Rationals A176726(n)/A176727(n): [1, 0, -2/3, 0, -32/15, 0, -704/21,0,...].

MATHEMATICA

max = 63; s = x/Log[Sqrt[(1+x)/(1-x)]] + O[x]^max; CoefficientList[s, x] * Range[0, max-1]! // Denominator (* Jean-Fran├žois Alcover, Oct 04 2016 *)

CROSSREFS

A176728/A176729 z-sequence for triangle A060081.

Sequence in context: A335265 A141459 A318142 * A080924 A232179 A128042

Adjacent sequences:  A176724 A176725 A176726 * A176728 A176729 A176730

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang, Jul 14 2010

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 October 28 15:26 EDT 2021. Contains 348329 sequences. (Running on oeis4.)