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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071239 n*(n+1)*(n^2+2)/6. 1
0, 1, 6, 22, 60, 135, 266, 476, 792, 1245, 1870, 2706, 3796, 5187, 6930, 9080, 11696, 14841, 18582, 22990, 28140, 34111, 40986, 48852, 57800, 67925, 79326, 92106, 106372, 122235, 139810, 159216, 180576, 204017, 229670, 257670, 288156, 321271, 357162, 395980 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Number of binary pattern classes with 4 black beads in the (2,n)-rectangular grid; two patterns are in the same class if one of them can be obtained by reflexion or rotation of the other one. [From Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Sep 12 2008]

REFERENCES

T. A. Gulliver, Sequences from Arrays of Integers, Int. Math. Journal, Vol. 1, No. 4, pp. 323-332, 2002.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

PROG

(MAGMA) [n*(n+1)*(n^2+2)/6: n in [0..40]]; // Vincenzo Librandi, Jun 14 2011

CROSSREFS

Cf. A132390 [From Yosu Yurramendi (yosu.yurramendi(AT)ehu.es), Sep 12 2008]

Sequence in context: A081441 A127760 A066188 * A105450 A011888 A081282

Adjacent sequences:  A071236 A071237 A071238 * A071240 A071241 A071242

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Jun 12 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 16:59 EST 2012. Contains 205636 sequences.