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A022279
a(n) = n*(21*n + 1)/2.
2
0, 11, 43, 96, 170, 265, 381, 518, 676, 855, 1055, 1276, 1518, 1781, 2065, 2370, 2696, 3043, 3411, 3800, 4210, 4641, 5093, 5566, 6060, 6575, 7111, 7668, 8246, 8845, 9465, 10106, 10768, 11451, 12155
OFFSET
0,2
FORMULA
a(n) = 21*n + a(n-1) - 10 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
a(0)=0, a(1)=11, a(2)=43; for n>2, a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Harvey P. Dale, May 06 2014
a(n) = A000217(11*n) - A000217(10*n). - Bruno Berselli, Oct 13 2016
From G. C. Greubel, Aug 23 2017: (Start)
G.f.: x*(10*x + 11)/(1-x)^3.
E.g.f.: (x/2)*(21*x + 22)*exp(x). (End)
MATHEMATICA
Table[n (21 n + 1)/2, {n, 0, 100}] (* Vladimir Joseph Stephan Orlovsky, Mar 07 2011 *)
LinearRecurrence[{3, -3, 1}, {0, 11, 43}, 40] (* Harvey P. Dale, May 06 2014 *)
PROG
(PARI) a(n)=n*(21*n+1)/2 \\ Charles R Greathouse IV, Jun 16 2017
CROSSREFS
Cf. similar sequences listed in A022289.
Sequence in context: A023299 A031904 A305708 * A141086 A352966 A142039
KEYWORD
nonn,easy
STATUS
approved