OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = (1/6)*(80*n^3 - 102*n^2 + 28*n).
a(n) = ((n-1)+1)*(5*(n-1)+3)*(8*(n-1)+1)/3; g.f.: x*(1 + 44*x + 35*x^2)/(1-x)^4. - Jaume Oliver Lafont, Sep 08 2009
PROG
(Magma) [((n-1)+1)*(5*(n-1)+3)*(8*(n-1)+1)/3: 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