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

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A058371 The sequence S defined in A058540. 3
0, 0, 1, 3, 12, 48, 217, 1005, 4878, 24218, 123021, 634995, 3323963, 17596131, 94053675, 506865965, 2751093957, 15025119759, 82511460766, 455331632088, 2523688452540, 14042621802676, 78415665739800, 439298161502112, 2468288819015277 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..24.

MAPLE

spec := [ S, {N=Union(Z, S, P, Q), S=Set(Union(Z, P, Q), card>=2), P=Set(Union(Z, S, Q), card>=2), Q=Set(Union(Z, S, P), card>=2)} ]; [seq(combstruct[count](spec, size=n), n=0..40)]; # N=A058540, S=A058371

spec:=[S, {S=Set(Union(Z, S, S), card>=2)}]; [seq(combstruct[count](spec, size=n), n=0..25)]; - Vladeta Jovovic, Jun 25 2007

CROSSREFS

Cf. A058575.

Sequence in context: A142873 A151168 A151169 * A226443 A060113 A134589

Adjacent sequences:  A058368 A058369 A058370 * A058372 A058373 A058374

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 26 2000

STATUS

approved

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

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

Last modified November 28 21:04 EST 2014. Contains 250406 sequences.