OFFSET
1,2
COMMENTS
EXAMPLE
floor(1000 / 7) = 142 and 1 + 4 + 2 = 7, hence 7 belongs to this sequence.
floor(1 / 5) = 0 and floor ((10^p) / 5) = 2 for any p > 0, hence 5 does not belong to this sequence.
PROG
(PARI) is(n) = my (r=1/n, s=0); while (r, s+=floor(r); if (s==n, return (1), s>n, return (0); r = frac(r)*10); return (0)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Rémy Sigrist, Jan 31 2018
STATUS
approved