A052424 Numbers k with no single-digit factors (apart from 1 and k).

1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 127, 131, 137, 139, 143, 149, 151, 157, 163, 167, 169, 173, 179, 181, 187, 191, 193, 197, 199, 209, 211, 221, 223, 227, 229, 233, 239

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Prog

(PARI) isok(n) = {d = divisors(n); for (i = 2, #d - 1, if (length(Str(d[i])) == 1, return (0)); ); return (1); } \\ Michel Marcus, Jul 27 2013

Crossrefs

Cf. A008364.

Sequence in context: A110923 A137589 A301378 * A055398 A070159 A322394

Adjacent sequences: A052421 A052422 A052423 * A052425 A052426 A052427

Keyword

nonn,base

Author

Henry Bottomley, Mar 14 2000

Status

approved