OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
t = Cases[Range[1, 16 (10^6), 2], n_ /; Mod[n, CarmichaelLambda@ n] == 1 && ! PrimeQ@ n]; Table[GCD[EulerPhi@ t[[n]], t[[n]] - 1]/CarmichaelLambda@ t[[n]], {n, 105}] (* Michael De Vlieger, Nov 03 2015, after Artur Jasinski at A002997: alternatively use A002997 data for t *)
PROG
(PARI) t(n)=my(f=factor(n)); for(i=1, #f[, 1], if(f[i, 2]>1||(n-1)%(f[i, 1]-1), return(0))); 1;
is(n)=n%2 && !isprime(n) && t(n) && n>1;
c(n)=gcd(eulerphi(n), n-1)/lcm(znstar(n)[2]);
for(n=1, 1e7, if(is(n), print1(c(n)", "))) \\ Altug Alkan, Nov 01 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Thomas Ordowski, Nov 01 2015
EXTENSIONS
More terms from Altug Alkan, Nov 01 2015
STATUS
approved