OFFSET
1,1
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..1000
EXAMPLE
105 is the smallest odd number such that 2*phi(n) < n, but phi(105) = 48 = phi(104), so 105 is not in the sequence.
PROG
(PARI) evenphimatch(n)=local(ph, i, r); ph=eulerphi(n); r=0; forstep(i=2*ph, n-1, 2, if(eulerphi(i)==ph, r=i; break)); r
nextoddlowphi(n)=while(2*eulerphi(n)>n, n+=2); n
i=1; while(i<1000000, i=nextoddlowphi(i+2); if(evenphimatch(i)==0, print(i)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Franklin T. Adams-Watters, May 20 2006
STATUS
approved