A078237 a(1) = 6, a(n+1) = smallest multiple of a(n) using only digits (4,6,8,9,0) and not divisible by 10.

6, 48, 96, 864, 6048, 489888, 460984608, 4880444044896, 6604089990008099904, 6406898466996448048966464, 488494490499084904898890846098449664

Offset

1,1

Comments

Sequence is infinite - see Comments in A078233. - Fung Cheok Yin (cheokyin_restart(AT)yahoo.com.hk), Sep 02 2006

Terms after a(8) have at least 18 digits. - R. J. Mathar, Apr 01 2007

Links

Table of n, a(n) for n=1..11.

Maple

A078237 := proc(nmax) local a, k, anext, baddigs, overl; a := [6] ; baddigs := {1, 2, 3, 5, 7} ; while nops(a) <nmax do k := 2 ; while true do anext := k*op(-1, a) ; overl := baddigs intersect convert(convert(anext, base, 10), set) ; if ( anext mod 10 <> 0) and nops(overl) = 0 then a := [op(a), anext] ; print(a); break ; else k := k+1 ; fi ; od ; od ; RETURN(a) ; end: A078237(20) ; # R. J. Mathar, Apr 01 2007

Crossrefs

Cf. A078236, A078238.

Sequence in context: A357430 A323138 A000252 * A274131 A341683 A259121

Adjacent sequences: A078234 A078235 A078236 * A078238 A078239 A078240

Keyword

base,more,nonn

Author

Amarnath Murthy, Nov 23 2002

Extensions

a(7) from Jonathan Vos Post, Mar 22 2006

a(8) from R. J. Mathar, Apr 01 2007

More terms from Robert Gerbicz, May 09 2008

a(11) from Donovan Johnson, Sep 05 2008

Status

approved