A113624 7-smooth numbers containing only composite digits (0,4,6,8,9).

4, 6, 8, 9, 40, 48, 49, 60, 64, 80, 84, 90, 96, 98, 400, 448, 480, 486, 490, 600, 640, 648, 686, 800, 840, 864, 896, 900, 960, 980, 4000, 4096, 4480, 4608, 4800, 4860, 4900, 6000, 6048, 6400, 6480, 6804, 6860, 8000, 8064, 8400, 8640, 8960, 9000, 9408, 9600

Offset

1,1

Links

Table of n, a(n) for n=1..51.

Example

96 is a term as 96 = 2^5*3 and contains digits 9,6 both composite. 96 is a member of A002473.

Mathematica

Select[Select[Range[2, 10000], FactorInteger[ # ][[ -1]][[1]] <= 7 &], DigitCount[ # ][[1]]+DigitCount[ # ][[2]]+DigitCount[ # ][[3]]+DigitCount[ # ][[5]]+ DigitCount[ # ][[7]] == 0 &] (* Stefan Steinerberger, Apr 11 2006 *)

Crossrefs

Intersection of A001744 and A002473.

Cf. A113623.

Sequence in context: A372408 A202260 A001744 * A113591 A029581 A202262

Adjacent sequences: A113621 A113622 A113623 * A113625 A113626 A113627

Keyword

base,nonn

Author

Amarnath Murthy, Nov 10 2005

Extensions

More terms from Stefan Steinerberger, Apr 11 2006

Name corrected and offset changed by Andrew Howroyd, Sep 17 2024

Status

approved