A011914 a(n) = floor(n*(n - 1)*(n - 2)/32).

0, 0, 0, 0, 0, 1, 3, 6, 10, 15, 22, 30, 41, 53, 68, 85, 105, 127, 153, 181, 213, 249, 288, 332, 379, 431, 487, 548, 614, 685, 761, 842, 930, 1023, 1122, 1227, 1338, 1456, 1581, 1713, 1852, 1998, 2152, 2313, 2483, 2660, 2846, 3040, 3243, 3454, 3675, 3904, 4143, 4392, 4650, 4919, 5197, 5486, 5785, 6095, 6416, 6748, 7091, 7445, 7812, 8190

Offset: 0

Author

N. J. A. Sloane, Dec 11 1996

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..2000
• Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,-3,3,-1).

Crossrefs

Cf. A011886.

Programs

Magma

[Floor(n*(n-1)*(n-2)/32): n in [0..80]]; // Wesley Ivan Hurt, Jun 02 2014

Maple

A011914:=n->floor(n*(n-1)*(n-2)/32); seq(A011914(n), n=0..80); # Wesley Ivan Hurt, Jun 02 2014

Mathematica

Table[Floor[n (n-1)(n-2)/32], {n,0,80}] (* Wesley Ivan Hurt, Jun 02 2014 *)

PARI

a(n) = n*(n-1)*(n-2)\32 \\ Jianing Song, Oct 15 2018

SageMath

[3*binomial(n,3)//16 for n in range(81)] # G. C. Greubel, Oct 20 2024

Formula

G.f.: x^5*(1-x+x^2)*(1 +x -x^3 -x^4 +x^5 +x^6 +2*x^7 -x^8 -x^9 -x^10 +x^11 +x^12 +2*x^13 -x^14 -x^15 +2*x^18 -x^21 +x^23 +x^24 -x^26 +x^27)/((1-x)^4*(1 +x)*(1+x^2)*(1+x^4)*(1+x^8)*(1+x^16)). - Peter J. C. Moses, Jun 02 2014

Extensions

More terms added by G. C. Greubel, Oct 20 2024