login
A185019
a(n) = n*(14*n-3).
19
0, 11, 50, 117, 212, 335, 486, 665, 872, 1107, 1370, 1661, 1980, 2327, 2702, 3105, 3536, 3995, 4482, 4997, 5540, 6111, 6710, 7337, 7992, 8675, 9386, 10125, 10892, 11687, 12510, 13361, 14240, 15147, 16082, 17045, 18036, 19055, 20102, 21177, 22280, 23411, 24570
OFFSET
0,2
FORMULA
G.f.: x*(11+17*x)/(1-x)^3.
a(n) = A195025(-n).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 3. - Wesley Ivan Hurt, Dec 18 2020
MATHEMATICA
CoefficientList[Series[x (11 + 17 x)/(1 - x)^3, {x, 0, 45}], x] (*Vincenzo Librandi_, Aug 18 2013 *)
PROG
(PARI) for(n=0, 42, print1(n*(14*n-3)", "));
(Magma) [n*(14*n-3): n in [0..42]];
(Magma) I:=[0, 11, 50]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+Self(n-3): n in [1..50]]; // Vincenzo Librandi, Aug 18 2013
CROSSREFS
Cf. A195020 (vertices of the numerical spiral in link).
Sequence in context: A306425 A241406 A215728 * A212560 A341735 A340130
KEYWORD
nonn,easy
AUTHOR
Bruno Berselli, Oct 14 2011 - based on remarks and sequences by Omar E. Pol
STATUS
approved