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A078223
a(1) = 2, a(n+1) > a(n) is the smallest multiple of a(n) using only even digits but not divisible by 10 (i.e., having no trailing zeros).
10
2, 4, 8, 24, 48, 288, 864, 6048, 260064, 26266464, 40082624064, 866826828008064, 26444286042042008448, 20286626620462624006244884224, 22488068646246262608620204848404846444288, 284860000088022466828484860444044822420060828284646488064
OFFSET
1,1
MATHEMATICA
a[n_] := a[n] = Block[{k = 2, b = a[n - 1], c = 2 Range[0, 4]}, While[Mod[k*b, 10]==0 || Union@ Join[c, IntegerDigits[k*b]] != c, k++]; k*b]; a[1] = 2; Array[a, 14] (* Robert G. Wilson v, May 26 2014 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Nov 23 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 06 2003
a(14) from Jon E. Schoenfield, Jun 04 2007
a(15) from Chai Wah Wu, Nov 20 2019
a(16) from Chai Wah Wu, Nov 29 2019
STATUS
approved