OFFSET
0,1
LINKS
T. D. Noe, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (120,-5075,100080,-1023828,5604480,-15915200,21073920,-9834496).
FORMULA
G.f.: -2*(10536960*x^7 -15915200*x^6 +8406720*x^5 -2047656*x^4 +250200*x^3 -15225*x^2 +420*x -4) / ((x -1)*(2*x -1)*(4*x -1)*(7*x -1)*(8*x -1)*(14*x -1)*(28*x -1)*(56*x -1)). - Colin Barker, May 03 2014
MATHEMATICA
Total[#^Range[0, 20]&/@Divisors[56]] (* Vincenzo Librandi, Apr 17 2014 *)
PROG
(Magma) [DivisorSigma(n, 56): n in [0..15]]; // Vincenzo Librandi, Apr 17 2014
(PARI) vector(30, n, sigma(56, n-1)) \\ Colin Barker, May 03 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved