A225295 Pandigital numbers with exactly 4 prime factors (with multiplicity).

1023456987, 1023458679, 1023458967, 1023465798, 1023465897, 1023465978, 1023465987, 1023467589, 1023467859, 1023468579, 1023468597, 1023468795, 1023469758, 1023478569, 1023479586, 1023479865, 1023485967, 1023486579, 1023486957, 1023487659, 1023487965, 1023489657, 1023495678

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Formula

A014613 INTERSECTION A171102.

a(n) ~ 6n log n / (log log n)^3. - Charles R Greathouse IV, May 04 2013

Example

a(1) = 1023456987 = 3^2 * 7 * 16245349.
a(2) = 1023458679 = 3^3 * 37905877.
a(3) = 1023458967 = 3^2 * 113 * 1006351.
a(4) = 1023465897 = 3^2 * 6379 * 17827.
a(5) = 1023465987 = 3^2 * 53 * 2145631.
a(511032) = 10123456987 = 7^2 * 9833 * 21011.

Prog

(PARI) is(n)=#vecsort(digits(n), , 8)>9 && bigomega(n)==4 \\ Charles R Greathouse IV, May 04 2013

Crossrefs

Cf. A001358, A014613, A221646.

Cf. A050288 (pandigital primes), A175845 (pandigital numbers).

Cf. A171102 (3-almost primes).

Sequence in context: A204047 A051264 A175845 * A036745 A225218 A359342

Adjacent sequences: A225292 A225293 A225294 * A225296 A225297 A225298

Keyword

nonn,base,easy

Author

Jonathan Vos Post, May 04 2013

Extensions

a(6)-a(23) from Charles R Greathouse IV, May 04 2013

Status

approved