A011942 - OEIS

A011942

a(n) = floor( n*(n-1)*(n-2)*(n-3)/32 ).

0, 0, 0, 0, 0, 3, 11, 26, 52, 94, 157, 247, 371, 536, 750, 1023, 1365, 1785, 2295, 2907, 3633, 4488, 5486, 6641, 7969, 9487, 11212, 13162, 15356, 17813, 20553, 23598, 26970, 30690, 34782, 39270, 44178, 49533, 55361, 61688, 68542, 75952, 83947, 92557, 101813, 111746, 122388, 133773, 145935, 158907, 172725

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,6

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..2500

Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-6,6,-10,10,-6,6,-10,10,-6,6,-10,10,-5,1).

FORMULA

From R. J. Mathar, Apr 15 2010: (Start)

a(n) = +5*a(n-1) -10*a(n-2) +10*a(n-3) -6*a(n-4) +6*a(n-5) -10*a(n-6) +10*a(n-7) -6*a(n-8) +6*a(n-9) -10*a(n-10) +10*a(n-11) -6*a(n-12) +6*a(n-13) -10*a(n-14) +10*a(n-15) -5*a(n-16) +a(n-17).

G.f.: x^5*(1-x+x^2)*(3-x-3*x^2+5*x^4-3*x^6-x^7+3*x^8)/((1-x)^5*(1+x^4)*(1+x^8) ). (End)

MATHEMATICA

Floor[3*Binomial[Range[0, 60], 4]/4] (* G. C. Greubel, Oct 26 2024 *)

PROG

(Magma) [Floor(3*Binomial(n, 4)/4): n in [0..60]]; // G. C. Greubel, Oct 26 2024

(SageMath) [3*binomial(n, 4)//4 for n in range(61)] # G. C. Greubel, Oct 26 2024

CROSSREFS

Cf. A011915.

Sequence in context: A272296 A051925 A211811 * A220147 A256315 A376752

Adjacent sequences: A011939 A011940 A011941 * A011943 A011944 A011945

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms added by G. C. Greubel, Oct 26 2024

STATUS

approved

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.