\\ describe a fraction: \\ - integer part \\ - transient part \\ - periodic part fracdigits(v, base) = { \\ integer part my (int=digits(floor(v), base)); \\ period length my (den=denominator(v), pr=factor(base)[,1]~, p=znorder(Mod(base, den / prod(i=1, #pr, pr[i]^valuation(den,pr[i]))))); \\ transient part my (tra=[], fra=frac(v)); while (fra != frac(fra*base^p), tra = concat(tra, floor(fra*base)); fra = frac(fra*base); ); \\ periodic part my (per = vector(p, x, my (d=floor(fra*base)); fra = frac(fra*base); d)); return ([int,tra,per]); } is(n, base=10) = #Set(select(sign, concat(fracdigits(1/n, base))))==1 for (n=1, oo, if (is(n), print (k++ " " n); if (k==1000, break))) quit