login
This site is supported by donations to The OEIS Foundation.

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A011874 [ n(n-1)/21 ]. 1
0, 0, 0, 0, 0, 0, 1, 2, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 33, 36, 38, 41, 44, 47, 50, 53, 56, 60, 63, 66, 70, 74, 78, 82, 86, 90, 94, 98, 102, 107, 112, 116, 121, 126, 131, 136, 141 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,8

LINKS

Table of n, a(n) for n=0..55.

FORMULA

G.f.: x^6(1-x^2+x^3+x^9-x^10+x^12)/((1-x)^2*(1-x^21)). [From R. J. Mathar, Sep 09 2008]

CROSSREFS

Sequence in context: A017896 A118868 A017885 * A000115 A033552 A062420

Adjacent sequences:  A011871 A011872 A011873 * A011875 A011876 A011877

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 29 10:48 EDT 2017. Contains 287246 sequences.