/* Test cases */
/* Long primes up to 500 */
sublist(makelist(i,i,500),lambda([x],primep(x) and zn_order(10,x)=x-1));

/* Number of long primes up to a specified limit */
length(sublist(makelist(i,i,500),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,1000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,2000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,4000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,8000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,16000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,32000),lambda([x],primep(x) and zn_order(10,x)=x-1)));
length(sublist(makelist(i,i,64000),lambda([x],primep(x) and zn_order(10,x)=x-1)));