OFFSET
1,3
COMMENTS
LINKS
PROG
(PARI) is(n, base = 2) = { my (d = digits(n, base)); for (i = 1, #d-2, forstep (j = i+2, #d, 2, if (d[i]==d[j] && d[i]==d[(i+j)/2], return (0); ); ); ); return (1); }
CROSSREFS
KEYWORD
nonn,base,easy,fini,full
AUTHOR
Rémy Sigrist, Jan 07 2024
STATUS
approved