login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A036099 Centered cube numbers: (n+1)^21 + n^21. 3
1, 2097153, 10462450355, 4408506864307, 481235204714229, 22413787798580981, 580482814723661863, 9781917900938059815, 118642361168367135017, 1109418989131512359209, 8400249944258160101211, 53405369853627861567323 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

After a(0) always has at least 4 prime factors, because a(n) = (2n + 1) * (n^2 + n + 1) * (n^6 + 3n^5 + 9n^4 + 13n^3 + 11n^2 + 5n + 1) * (n^12 + 6n^11 + 63n^10 + 260n^9 + 643n^8 + 1078n^7 + 1275n^6 + 1078n^5 + 650n^4 + 274n^3 + 77n^2 + 13n + 1). [Jonathan Vos Post, Aug 27 2011]

REFERENCES

B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

MATHEMATICA

Total/@Partition[Range[0, 20]^21, 2, 1] (* Harvey P. Dale, Jul 02 2019 *)

PROG

(Magma) [(n+1)^21+n^21: n in [0..20]]; // Vincenzo Librandi, Aug 28 2011

CROSSREFS

Cf. A010809, A036098, A036097.

Sequence in context: A323659 A017705 A013969 * A253058 A233979 A203786

Adjacent sequences:  A036096 A036097 A036098 * A036100 A036101 A036102

KEYWORD

nonn,easy

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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 3 22:17 EDT 2022. Contains 357237 sequences. (Running on oeis4.)