OFFSET
1,2
COMMENTS
Number of divisors of 120^(n-1). - J. Lowell, Aug 30 2008
Partial sums of A214675. - J. M. Bergot, Jul 08 2013
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = 3*n^3 - 2*n^2.
G.f.: x*(1+12*x+5*x^2)/(1-x)^4. - Colin Barker, Jun 08 2012
a(n) = Sum_{i=0..n-1} n*(6*i+1). - Bruno Berselli, Sep 08 2015
Sum_{n>=1} 1/a(n) = sqrt(3)*Pi/8 - Pi^2/12 + 9*log(3)/8 = 1.0936465529153418... . - Vaclav Kotesovec, Oct 04 2016
MAPLE
[seq(3*n^3-2*n^2, n=1..47)]; # Zerinvary Lajos, Jun 29 2006
MATHEMATICA
f[n_] := 3 n^3 - 2 n^2; Table[f[n], {n, 0, 50}] (* Vladimir Joseph Stephan Orlovsky, Apr 27 2010 *)
PROG
(Magma) [3*n^3-2*n^2: n in [1..50] ]; // Vincenzo Librandi, Aug 02 2011
(PARI) a(n)=3*n^3-2*n^2 \\ Charles R Greathouse IV, Aug 10 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
James A. Record (james.record(AT)gmail.com), Nov 07 2004
EXTENSIONS
More terms from Zerinvary Lajos, Jun 29 2006
STATUS
approved