OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = (1/6)*(116*n^3 - 168*n^2 + 58*n).
G.f.: x*(1+x)*(1+57*x)/(1-x)^4. [Colin Barker, Apr 16 2012]
PROG
(Magma) [(1/6)*(116*n^3-168*n^2+58*n): n in [1..40]]; // Vincenzo Librandi, Jul 19 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
James A. Record (james.record(AT)gmail.com), Nov 07 2004
STATUS
approved