OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (72,-1942,25992,-190081,779760,-1747800,1944000,-810000).
FORMULA
G.f.: (8 - 504*x + 11652*x^2 - 129960*x^3 + 760324*x^4 - 2339280* x^5 + 3495600*x^6 - 1944000*x^7) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 5*x)*(1 - 6*x)*(1 - 10*x)*(1 - 15*x)*(1 - 30*x)).
a(n) = (1 + 2^n)*(1 + 3^n)*(1 + 5^n).
MATHEMATICA
Total[#^Range[0, 20] & /@ Divisors[30]]
PROG
(Magma) [DivisorSigma(n, 30): n in [0..20]];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 17 2014
STATUS
approved