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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A309673 Number of n-bead necklace structures using a maximum of four different colored beads and no adjacent beads having the same color. 4
0, 1, 1, 3, 2, 9, 13, 41, 94, 257, 671, 1881, 5110, 14301, 39871, 112281, 316520, 897297, 2548819, 7265383, 20754748, 59437181, 170549237, 490338539, 1412147684, 4073528481, 11767897903, 34042917197, 98606864030, 285960106473, 830206177801, 2412787265021 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Colors may be permuted without changing the necklace structure.

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..200

FORMULA

a(n) = Sum_{k=1..4} A327396(n, k).

CROSSREFS

Cf. A056292, A306888, A327396, A328130.

Sequence in context: A077898 A303631 A076584 * A154343 A049969 A088634

Adjacent sequences:  A309670 A309671 A309672 * A309674 A309675 A309676

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Oct 05 2019

EXTENSIONS

Terms a(24) and beyond from Andrew Howroyd, Oct 10 2019

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 November 30 19:02 EST 2021. Contains 349424 sequences. (Running on oeis4.)