OFFSET
1,2
REFERENCES
P. A. MacMahon, The connexion between the sum of the squares of the divisors and the number of partitions of a given number, Messenger Math., 54 (1924), 113-116. Collected Papers, MIT Press, 1978, Vol. I, pp. 1364-1367.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MAPLE
with(numtheory):
A:=proc(s, n) local d, s1, s2;
s1:=0; s2:=0;
for d in divisors(n) do
if d <= s then s1:=s1+d^2 else s2:=s2+d; fi; od:
s1+s*s2; end;
f:=s->[seq(A(s, n), n=1..80)];
f(5);
MATHEMATICA
sd5[n_]:=Module[{d=Divisors[n]}, Total[Select[d, #<6&]^2]+5Total[Select[ d, #>5&]]]; Array[sd5, 70] (* Harvey P. Dale, Mar 18 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 21 2014
EXTENSIONS
Typo in definition corrected by N. J. A. Sloane, Mar 18 2015
STATUS
approved