A085889 7-smooth numbers (A002473) using digits in increasing order. 9 is followed by a zero.

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 45, 56, 90, 567, 3456

Offset: 1

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 10 2003

Keywords

• base
• nonn

Comments

No more terms < 10^1000. Probably no more terms. - David Wasserman, Feb 10 2005

Examples

			567 is a member as 567 = 3^4*7.
		

Crossrefs

Intersection of A002473 and A059043.

Cf. A085890.

Programs

PARI

hcn(n) = while (!(n%2), n \=2); while (!(n%3), n \=3); while (!(n%5), n \=5); while (!(n%7), n \=7); n == 1;
for (i = 0, 1000, for (j = 1, 9, my(n = sum(k = j, i + j, (k%10)*10^(i + j - k))); if (hcn(n), print1(n, ", ")))); /* David Wasserman, Feb 10 2005 */

Extensions

3456 from David Wasserman, Feb 10 2005