OFFSET
0,2
PROG
(PARI) is(n, b) = for (w=1, oo, my (d=digits(n, b^w)); if (#d<=1, return (0), #Set(d)==1, return (1))) \\ after Rémy Sigrist in A321513
a353339(n) = my(i=0); for(b=2, n-1, if(is(n, b), i++)); i
a(n) = for(k=1, oo, if(a353339(k)==n, return(k)))
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Felix Fröhlich, Apr 14 2022
STATUS
approved