OFFSET
1,5
FORMULA
a(n) = (2*n+3-(-1)^n+2*(-1)^((2*n+5-(-1)^n)/4))*(n^3+7*n^2+19*n+113-(n^3-n^2+19*n-15)*(-1)^n-(n^3+7*n^2-13*n-111)*(-1)^((2*n+5-(-1)^n)/4)-(n^3-n^2-13*n+17)*(-1)^((2*n+7+(-1)^n)/4))/2048. - Luce ETIENNE, Sep 01 2016
From Chai Wah Wu, Jan 11 2020: (Start)
a(n) = 5*a(n-4) - 10*a(n-8) + 10*a(n-12) - 5*a(n-16) + a(n-20) for n > 20.
G.f.: x*(x^15 - x^14 + x^13 - x^12 + 3*x^11 - 11*x^10 - 3*x^9 + x^8 - 3*x^7 - 11*x^6 + 3*x^5 + x^4 - x^3 - x^2 - x - 1)/((x - 1)^5*(x + 1)^5*(x^2 + 1)^5). (End)
MATHEMATICA
Flatten[Table[{n^2, n, n^4, n^3}, {n, 20}]] (* Harvey P. Dale, Oct 24 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Mohammad K. Azarian, Sep 14 2005
STATUS
approved