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

1,2

Comments

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

Links

Table of n, a(n) for n=1..15.

Example

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

Prog

(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 */

Crossrefs

Intersection of A002473 and A059043.

Cf. A085890.

Sequence in context: A302504 A165307 A081549 * A342951 A342264 A094823

Adjacent sequences: A085886 A085887 A085888 * A085890 A085891 A085892

Keyword

base,nonn

Author

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

Extensions

3456 from David Wasserman, Feb 10 2005

Status

approved