OFFSET
1,1
MATHEMATICA
Do[ i = 0; l = Ceiling[ N[ Log[ 3, n ] ] ]; While[ ! PrimeQ[ n - 3^i ] && i < l, i++ ]; If[ i == l, Print[ n ] ], {n, 2, 1000, 2} ]
PROG
(PARI) isok(n) = {if (n % 2, 0, lim = log(n)/log(3); for (k=0, lim, if (isprime(n - 3^k), return (0)); ); 1; ); } \\ Michel Marcus, Feb 25 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Dec 21 2000
STATUS
approved