|
|
A103637
|
|
a(n) = Sum_{d|n, d==1 mod 3} d^2.
|
|
3
|
|
|
1, 1, 1, 17, 1, 1, 50, 17, 1, 101, 1, 17, 170, 50, 1, 273, 1, 1, 362, 117, 50, 485, 1, 17, 626, 170, 1, 850, 1, 101, 962, 273, 1, 1157, 50, 17, 1370, 362, 170, 1717, 1, 50, 1850, 501, 1, 2117, 1, 273, 2451, 726, 1, 2890, 1, 1, 3026, 850, 362, 3365, 1, 117, 3722
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
LINKS
|
|
|
MATHEMATICA
|
a[n_] := DivisorSum[n, #^2 &, Mod[#, 3] == 1 &]; Array[a, 100] (* Amiram Eldar, Jun 30 2023 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|