A094160 Column 4 of A048790.

0, 4, 76, 344, 936, 1980, 3604, 5936, 9104, 13236, 18460, 24904, 32696, 41964, 52836, 65440, 79904, 96356, 114924, 135736, 158920, 184604, 212916, 243984, 277936, 314900, 355004, 398376, 445144, 495436, 549380, 607104, 668736, 734404, 804236

Offset: 1

Author

N. J. A. Sloane, May 05 2004

Keywords

• nonn
• easy

References

• Dan Hoey, Bill Gosper and Richard C. Schroeppel, Discussions in Math-Fun Mailing list, circa Jul 13 1999.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• R. C. Schroeppel, A few mathematical experiments, Experimental Mathematics Workshop, Oakland, California, March 30, 2004.
• Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Programs

Magma

[64/3*n^3-30*n^2+38/3*n: n in [0..60]]; // Vincenzo Librandi, Aug 28 2016

Mathematica

Table[(64/3 n^3 - 30 n^2 + 38/3 n), {n, 0, 80}] (* Vincenzo Librandi, Aug 28 2016 *)

PARI

concat(0, Vec(4*x^2*(1+15*x+16*x^2)/(1-x)^4 + O(x^60))) \\ Colin Barker, Aug 28 2016

Formula

A polynomial in n of degree 3.

a(n) = 64/3 n^3 - 30 n^2 + 38/3 n. - Joshua Zucker, Aug 14 2006

From Colin Barker, Aug 28 2016: (Start)

a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4) for n>4.

G.f.: 4*x^2*(1+15*x+16*x^2) / (1-x)^4.

(End)

Extensions

More terms from Joshua Zucker, Aug 14 2006