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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A035806 Coordination sequence for lattice D*_42 (with edges defined by l_1 norm = 1). 2
1, 84, 3528, 98812, 2076816, 34949796, 490681688, 5913144396, 62456027424, 587522034932, 4985149915368, 38549117382300, 273998113272240, 1803067831236420, 11053262513080440, 63460928860322028, 342841481215636032, 1750035197354015124 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Starts to differ from A035737 at a(21). - R. J. Mathar, Oct 24 2008

REFERENCES

J. Serra-Sagrista, Enumeration of lattice points in l_1 norm, Information Processing Letters, 76, no. 1-2 (2000), 39-44.

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 0..500

Index entries for linear recurrences with constant coefficients, signature (42, -861, 11480, -111930, 850668, -5245786, 26978328, -118030185, 445891810, -1471442973, 4280561376, -11058116888, 25518731280, -52860229080, 98672427616, -166509721602, 254661927156, -353697121050, 446775310800, -513791607420, 538257874440, -513791607420, 446775310800, -353697121050, 254661927156, -166509721602, 98672427616, -52860229080, 25518731280, -11058116888, 4280561376, -1471442973, 445891810, -118030185, 26978328, -5245786, 850668, -111930, 11480, -861, 42, -1).

FORMULA

a(n) = (Sum_{k=0..m} 2^k*binomial(m, k)*binomial(n-1, k-1)) + 2^m*binomial((m+2*n)/2-1, m-1), with m=42.

MAPLE

seq(add(2^k*binomial(42, k)*binomial(n-1, k-1), k=0..42) + 2^42*binomial((42+2*n)/2-1, 41), n=0..21); # Nathaniel Johnston, Jun 26 2011

CROSSREFS

Sequence in context: A114253 A017800 A035737 * A017747 A223959 A143402

Adjacent sequences:  A035803 A035804 A035805 * A035807 A035808 A035809

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, J. Serra-Sagrista (jserra(AT)ccd.uab.es)

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 27 07:28 EST 2021. Contains 349365 sequences. (Running on oeis4.)