OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = A272398(4*n-3).
a(n) = 10-27*n+18*n^2.
a(n) = 3*a(n-1)-3*a(n-2)+a(n-3) for n>3.
G.f.: x*(1+25*x+10*x^2) / (1-x)^3.
E.g.f.: (9*x*(2*x - 1) + 10)*exp(x) - 10. - Ilya Gutkovskiy, Apr 28 2016
MATHEMATICA
Rest@ CoefficientList[Series[x (1 + 25 x + 10 x^2)/(1 - x)^3, {x, 0, 42}], x] (* Michael De Vlieger, Apr 28 2016 *)
PROG
(PARI) lista(nn) = for(n=1, nn, print1(10-27*n+18*n^2, ", ")); \\ Altug Alkan, Apr 28 2016
(PARI) a(n)=18*n^2-27*n+10 \\ Charles R Greathouse IV, Apr 28 2016
(PARI) Vec(x*(1+25*x+10*x^2) / (1-x)^3 + O(x^50)) \\ Colin Barker, Apr 29 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Apr 28 2016
STATUS
approved