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A366657
Sum of the divisors of 8^n+1.
9
3, 13, 84, 800, 4356, 51792, 351120, 3100240, 17041416, 211053040, 1494039792, 12611914848, 73234343952, 794382536272, 5936210280000, 60037292774400, 282937726148616, 3264911394064320, 24128875076496960, 208532141890460960, 1225825603154905104
OFFSET
0,1
LINKS
FORMULA
a(n) = sigma(8^n+1) = A000203(A062395(n)).
a(n) = A069061(3*n). - Max Alekseyev, Jan 09 2024
EXAMPLE
a(4)=4356 because 8^4+1 has divisors {1, 17, 241, 4097}.
MAPLE
a:=n->numtheory[sigma](8^n+1):
seq(a(n), n=0..100);
MATHEMATICA
DivisorSigma[1, 8^Range[0, 20]+1] (* Paul F. Marrero Romero, Nov 19 2023 *)
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 15 2023
STATUS
approved