OFFSET
1,2
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = (1/6)*(114*n^3 - 162*n^2 + 54*n) = n*(19*n^2 - 27*n + 9).
G.f.: x*(1 + 58*x + 55*x^2)/(1-x)^4. [Colin Barker, Apr 16 2012]
PROG
(Magma) [(1/6)*(114*n^3-162*n^2+54*n): n in [1..40]]; // Vincenzo Librandi, Jul 19 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
James A. Record (james.record(AT)gmail.com), Nov 07 2004
STATUS
approved