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A139577
a(n) = n*(2*n + 11).
6
0, 13, 30, 51, 76, 105, 138, 175, 216, 261, 310, 363, 420, 481, 546, 615, 688, 765, 846, 931, 1020, 1113, 1210, 1311, 1416, 1525, 1638, 1755, 1876, 2001, 2130, 2263, 2400, 2541, 2686, 2835, 2988, 3145, 3306, 3471, 3640, 3813, 3990
OFFSET
0,2
FORMULA
a(n) = 2*n^2 + 11*n.
a(n) = a(n-1) + 4*n + 9 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
MATHEMATICA
s=0; lst={s}; Do[s+=n++ +13; AppendTo[lst, s], {n, 0, 7!, 4}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)
Table[n(2n+11), {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 13, 30}, 50] (* Harvey P. Dale, Mar 17 2019 *)
PROG
(PARI) a(n)=n*(2*n+11) \\ Charles R Greathouse IV, Jun 17 2017
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, May 19 2008
STATUS
approved