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A022272
a(n) = n*(15*n - 1)/2.
5
0, 7, 29, 66, 118, 185, 267, 364, 476, 603, 745, 902, 1074, 1261, 1463, 1680, 1912, 2159, 2421, 2698, 2990, 3297, 3619, 3956, 4308, 4675, 5057, 5454, 5866, 6293, 6735, 7192, 7664, 8151, 8653, 9170, 9702, 10249, 10811, 11388, 11980, 12587, 13209, 13846, 14498
OFFSET
0,2
FORMULA
a(n) = 15*n + a(n-1) - 8 for n>0, a(0)=0. - Vincenzo Librandi, Aug 04 2010
From Vincenzo Librandi, Mar 31 2015: (Start)
G.f.: x*(7 + 8*x)/(1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2. (End)
From Bruno Berselli, Mar 31 2015: (Start)
a(n) = A022273(-n).
a(n) + a(-n) = A064761(n). (End)
a(n) = A000217(8*n-1) - A000217(7*n-1). - Bruno Berselli, Oct 17 2016
E.g.f.: (x/2)*(15*x + 14)*exp(x). - G. C. Greubel, Aug 23 2017
MATHEMATICA
Table[n (15 n - 1)/2, {n, 0, 40}] (* Bruno Berselli, Mar 12 2015 *)
CoefficientList[Series[x (7 + 8 x) / (1 - x)^3, {x, 0, 40}], x] (* Vincenzo Librandi, Mar 31 2015 *)
LinearRecurrence[{3, -3, 1}, {0, 7, 29}, 50] (* Harvey P. Dale, Sep 15 2024 *)
PROG
(Magma) [n*(15*n - 1)/2: n in [0..45]]; // Vincenzo Librandi, Mar 31 20125
(PARI) a(n)=n*(15*n-1)/2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
Cf. similar sequences listed in A022288.
Sequence in context: A355920 A219835 A041621 * A185438 A265803 A176616
KEYWORD
nonn,easy
EXTENSIONS
More terms from Vincenzo Librandi, Mar 31 2015
STATUS
approved