A055811 a(n) = T(n,n-6), array T as in A055807.

1, 63, 192, 432, 832, 1452, 2364, 3653, 5418, 7773, 10848, 14790, 19764, 25954, 33564, 42819, 53966, 67275, 83040, 101580, 123240, 148392, 177436, 210801, 248946, 292361, 341568, 397122, 459612, 529662

Offset

6,2

Links

G. C. Greubel, Table of n, a(n) for n = 6..1000

Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

Formula

From G. C. Greubel, Jan 23 2020: (Start)

a(n) = n*(1584 - 310*n - 85*n^2 + 10*n^3 + n^4)/120 for n > 6, with a(6) = 1.

G.f.: x^6*(1 + 57*x - 171*x^2 + 205*x^3 - 125*x^4 + 39*x^5 - 5*x^6)/(1-x)^6.

E.g.f.: (-1)*x*(7200 +4320*x +720*x^2 -120*x^3 -54*x^4 +5*x^5 - (7200 -2880*x + 120*x^3 + 6*x^4)*exp(x))/720. (End)

Maple

seq( `if`(n=6, 1, n*(1584 -310*n -85*n^2 +10*n^3 +n^4)/120), n=6..30); # G. C. Greubel, Jan 23 2020

Mathematica

Table[If[n==6, 1, n*(1584 -310*n -85*n^2 +10*n^3 +n^4)/120], {n, 6, 30}] (* G. C. Greubel, Jan 23 2020 *)

Prog

(PARI) vector(25, n, my(m=n+5); if(m==6, 1, m*(1584 -310*m -85*m^2 +10*m^3 +m^4)/120) ) \\ G. C. Greubel, Jan 23 2020
(Magma) [1] cat [n*(1584 -310*n -85*n^2 +10*n^3 +n^4)/120: n in [7.30]]; // G. C. Greubel, Jan 23 2020
(Sage) [1]+[n*(1584 -310*n -85*n^2 +10*n^3 +n^4)/120 for n in (7..30)] # G. C. Greubel, Jan 23 2020
(GAP) Concatenation([1], List([7..30], n-> n*(1584 -310*n -85*n^2 +10*n^3 +n^4)/120 )); # G. C. Greubel, Jan 23 2020

Crossrefs

Cf. A055807, A055809, A055810, A055815, A055816, A055817.

Sequence in context: A143033 A156527 A199850 * A035329 A097973 A038644

Adjacent sequences: A055808 A055809 A055810 * A055812 A055813 A055814

Keyword

nonn,easy

Author

Clark Kimberling, May 28 2000

Status

approved