|
|
|
|
1, 4, 6, 16, 20, 48, 70, 160, 270, 560, 1034, 2160, 4108, 8344, 16440, 33088, 65552, 131688, 262162, 525440, 1048740, 2099240, 4194326, 8393184, 16777300, 33562672, 67109418, 134234464, 268435484, 536904960, 1073741854, 2147549824, 4294969404
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Table[DivisorSum[n, 2^#*EulerPhi[2 n/#] &]/2, {n, 33}] (* Michael De Vlieger, Dec 01 2019 *)
|
|
PROG
|
(PARI) a(n) = sumdiv(n, d, 2^(n/d-1)*eulerphi(2*d)); \\ Seiichi Manyama, Jul 14 2023
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|