OFFSET
1,3
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
FORMULA
MATHEMATICA
{1}~Join~Array[GCD[Total[-#*(-1)^Range[Length[#], 1, -1]] &@ Divisors[#], Times @@ (Sum[(-1)^(#2 - k)*#1^k, {k, 0, #2}] & @@@ FactorInteger[#])] &, 91, 2] (* Michael De Vlieger, Jul 06 2021, after Amiram Eldar at A071324 and A206369 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 07 2021
STATUS
approved