OFFSET
0,6
LINKS
Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -4, 6, -4, 1).
FORMULA
From Chai Wah Wu, Aug 02 2020: (Start)
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-27) - 4*a(n-28) + 6*a(n-29) - 4*a(n-30) + a(n-31) for n > 30.
G.f.: x^5*(-4*x^24 + 3*x^23 - 3*x^22 - 2*x^20 + x^19 - 4*x^18 + 2*x^17 - x^16 - 3*x^15 + x^13 - 4*x^12 + x^11 - 3*x^9 - x^8 + 2*x^7 - 4*x^6 + x^5 - 2*x^4 - 3*x^2 + 3*x - 4)/((x - 1)^5*(x^2 + x + 1)*(x^6 + x^3 + 1)*(x^18 + x^9 + 1)). (End)
MATHEMATICA
Table[Floor[n (n - 1) (n - 2) (n - 3)/27], {n, 0, 60}] (* Wesley Ivan Hurt, Jan 02 2024 *)
PROG
(PARI) a(n)=n*(n-1)*(n-2)*(n-3)\27 \\ Charles R Greathouse IV, Oct 18 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved