A085890 Highly composite numbers (A002473) using digits in descending order. 1 is followed by a zero.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 21, 32, 54, 98, 210, 432

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..16.

Example

432 is a member as 432= 2^4*3^3.

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, n = sum(k = j - i, j, (k%10)*10^(i - j + k)); if (hcn(n), print1(n, ", ")))); /* David Wasserman, Feb 10 2005 */

Crossrefs

Cf. A002473, A085889.

Sequence in context: A247107 A061511 A138142 * A274842 A134817 A067581

Adjacent sequences: A085887 A085888 A085889 * A085891 A085892 A085893

Keyword

base,nonn

Author

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

Extensions

More terms from David Wasserman, Feb 10 2005

Status

approved