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A010973 a(n) = binomial(n,20). 3
1, 21, 231, 1771, 10626, 53130, 230230, 888030, 3108105, 10015005, 30045015, 84672315, 225792840, 573166440, 1391975640, 3247943160, 7307872110, 15905368710, 33578000610, 68923264410, 137846528820, 269128937220, 513791607420, 960566918220, 1761039350070 (list; graph; refs; listen; history; text; internal format)
OFFSET

20,2

COMMENTS

Coordination sequence for 22-dimensional cyclotomic lattice Z[zeta_23].

In this sequence there are no primes. - Artur Jasinski, Dec 02 2007

LINKS

T. D. Noe, Table of n, a(n) for n = 20..1000

M. Beck and S. Hosten, Cyclotomic polytopes and growth series of cyclotomic lattices, arXiv:math/0508136 [math.CO], 2005-2006.

Milan Janjic, Two Enumerative Functions [Broken link]

FORMULA

a(n+19) = n*(n+1)*(n+2)*(n+3)*(n+4)*(n+5)*(n+6)*(n+7)*(n+8)*(n+9)*(n+10)*(n+11)*(n+12)*(n+13)*(n+14)*(n+15)*(n+16)*(n+17)*(n+18)*(n+19)/20!. - Artur Jasinski, Dec 02 2007, R. J. Mathar, Jul 07 2009

G.f.: x^20/(1-x)^21. - Zerinvary Lajos, Aug 04 2008, R. J. Mathar, Jul 07 2009

a(n) = n/(n-20) * a(n-1), n > 20. - Vincenzo Librandi, Mar 26 2011

MAPLE

(Maple) seq(binomial(n, 20), n=20..40); # Zerinvary Lajos, Aug 04 2008

MATHEMATICA

Table[Binomial[n, 20], {n, 20, 50}] (* Vladimir Joseph Stephan Orlovsky, Apr 22 2011 *)

(PARI) for(n=20, 50, print1(binomial(n, 20), ", ")) \\ G. C. Greubel, Nov 23 2017

PROG

(MAGMA) [ Binomial(n, 20): n in [20..80]]; // Vincenzo Librandi, Mar 26 2011

CROSSREFS

Pascal's triangle A007318 diagonal. - Zerinvary Lajos, Aug 04 2008

Sequence in context: A126902 A162646 A247615 * A022586 A125409 A161581

Adjacent sequences:  A010970 A010971 A010972 * A010974 A010975 A010976

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

Some formulas adjusted to the offset by R. J. Mathar, Jul 07 2009

STATUS

approved

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Last modified February 20 09:06 EST 2018. Contains 299384 sequences. (Running on oeis4.)