OFFSET
0,2
COMMENTS
Main diagonal of square array A239331.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
MATHEMATICA
CoefficientList[Series[(1 - 2 x + 8 x^2 + x^3 + 4 x^4)/(1 - x)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Mar 23 2014 *)
PROG
(PARI) Vec((1-2*x+8*x^2+x^3+4*x^4)/(1-x)^5 + O(x^100)) \\ Colin Barker, Mar 22 2014
(Magma) [(n^4-n^3+4*n^2 + 2)/2: n in [0..40]]; // Vincenzo Librandi, Mar 23 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Mar 22 2014
STATUS
approved