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A210675
a(n)=a(n-1)+a(n-2)+n+4, a(0)=0, a(1)=1.
1
0, 1, 7, 15, 30, 54, 94, 159, 265, 437, 716, 1168, 1900, 3085, 5003, 8107, 13130, 21258, 34410, 55691, 90125, 145841, 235992, 381860, 617880, 999769, 1617679, 2617479, 4235190, 6852702, 11087926, 17940663, 29028625, 46969325, 75997988, 122967352, 198965380
OFFSET
0,3
FORMULA
a(n) = 3*a(n-1)-2*a(n-2)-a(n-3)+a(n-4). G.f.: x*(4*x^2-4*x-1) / ((x-1)^2*(x^2+x-1)). - Colin Barker, May 31 2013
MATHEMATICA
LinearRecurrence[{3, -2, -1, 1}, {0, 1, 7, 15}, 37] (* Jean-François Alcover, Oct 05 2017 *)
CROSSREFS
Cf. A210673: a(n)=a(n-1)+a(n-2)+n-4, a(0)=0,a(1)=1.
Cf. A066982: a(n)=a(n-1)+a(n-2)+n-2, a(0)=0,a(1)=1 (except the first term).
Cf. A104161: a(n)=a(n-1)+a(n-2)+n-1, a(0)=0,a(1)=1.
Cf. A001924: a(n)=a(n-1)+a(n-2)+n, a(0)=0,a(1)=1.
Cf. A192760: a(n)=a(n-1)+a(n-2)+n+1, a(0)=0,a(1)=1.
Cf. A192761: a(n)=a(n-1)+a(n-2)+n+2, a(0)=0,a(1)=1.
Cf. A192762: a(n)=a(n-1)+a(n-2)+n+3, a(0)=0,a(1)=1.
Sequence in context: A299309 A300110 A139597 * A293361 A117747 A179882
KEYWORD
nonn,easy
AUTHOR
Alex Ratushnyak, May 09 2012
STATUS
approved