OFFSET
1,1
EXAMPLE
For n = 3, the divisors are 1 and 3, the sum is 2^1 * 3^3 + 2^3 * 3^1 = 54 + 24 = 78.
MATHEMATICA
Table[Total[2^Divisors[n] 3^(n/Divisors[n])], {n, 30}] (* Harvey P. Dale, Nov 08 2017 *)
PROG
(PARI) a(n) = sumdiv(n, d, 2^d*3^(n/d)); \\ Michel Marcus, Oct 05 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved