OFFSET
0,2
COMMENTS
Fourth column of table A210530 for n>0. - Boris Putievskiy, Jan 29 2013
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).
FORMULA
a(n) = 2*A065423(n+1).
O.g.f.: 2*x(2+x)/(1-x^2)^2. - Len Smiley, Dec 06 2001
a(n) = (3*n+2-(n+2)*(-1)^n)/2. - Boris Putievskiy, Jan 29 2013
MATHEMATICA
Table[(3*n+2-(n+2)*(-1)^n)/2, {n, 0, 50}] (* or *) LinearRecurrence[{0, 2, 0, -1}, {0, 4, 2, 8}, 50] (* G. C. Greubel, Dec 24 2016 *)
PROG
(PARI) { for (n=0, 1000, if(n%2, a=2*n + 2, a=n); write("b066104.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 14 2009
(PARI) concat([0], Vec(2*x*(x+2)/(1-x^2)^2 + O(x^50))) \\ G. C. Greubel, Dec 24 2016
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
George E. Antoniou, Dec 04 2001
STATUS
approved