A010980 a(n) = binomial(n,27).

1, 28, 406, 4060, 31465, 201376, 1107568, 5379616, 23535820, 94143280, 348330136, 1203322288, 3910797436, 12033222880, 35240152720, 98672427616, 265182149218, 686353797976, 1715884494940, 4154246671960, 9762479679106, 22314239266528, 49699896548176

Offset

27,2

Links

T. D. Noe, Table of n, a(n) for n = 27..1000

Index entries for linear recurrences with constant coefficients, signature (28, -378, 3276, -20475, 98280, -376740, 1184040, -3108105, 6906900, -13123110, 21474180, -30421755, 37442160, -40116600, 37442160, -30421755, 21474180, -13123110, 6906900, -3108105, 1184040, -376740, 98280, -20475, 3276, -378, 28, -1).

Formula

From Zerinvary Lajos, Aug 18 2008: (Start)

a(n) = C(n,27), n >= 27.

G.f.: x^27/(1-x)^28. (End)

From Amiram Eldar, Dec 11 2020: (Start)

Sum_{n>=27} 1/a(n) = 27/26.

Sum_{n>=27} (-1)^(n+1)/a(n) = A001787(27)*log(2) - A242091(27)/26! = 1811939328*log(2) - 233492834118075846/185910725 = 0.9665300296... (End)

Maple

seq(binomial(n, 27), n=27..51); # Zerinvary Lajos, Aug 18 2008

Mathematica

Table[Binomial[n, 27], {n, 27, 60}] (* Vladimir Joseph Stephan Orlovsky, Apr 26 2011 *)

Prog

(Magma) [Binomial(n, 27): n in [27..60]]; // Vincenzo Librandi, Jun 12 2013
(PARI) x='x+O('x^50); Vec(x^27/(1-x)^28) \\ G. C. Greubel, Nov 23 2017

Crossrefs

Cf. A010976, A010977, A010978, A001787, A242091.

Sequence in context: A161956 A162370 A162727 * A022592 A323973 A121798

Adjacent sequences: A010977 A010978 A010979 * A010981 A010982 A010983

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved