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A111386 a(1) = 1, a(2) = 3; for n >= 3, take a(n) to be the smallest odd number not occurring earlier such that a(n-1) divides the concatenation a(n-2)a(n). 2
1, 3, 5, 15, 25, 75, 125, 375, 625, 1875, 3125, 9375, 15625, 46875, 78125, 234375, 390625, 1171875, 1953125, 5859375, 9765625, 29296875, 48828125, 146484375, 244140625, 732421875, 1220703125, 3662109375, 6103515625, 18310546875, 30517578125 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Apparently identical to A056487! Is this a theorem? - Klaus Brockhaus, Jul 21 2009
LINKS
EXAMPLE
After 75 the term is 125 since 75 divides 25125.
CROSSREFS
Cf. A111387.
Sequence in context: A328834 A018421 A163114 * A056487 A146582 A349967
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 11 2005
EXTENSIONS
More terms from R. J. Mathar, Aug 20 2007
a(21)-a(31) from Donovan Johnson, Apr 27 2008
STATUS
approved

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Last modified March 29 08:01 EDT 2024. Contains 371265 sequences. (Running on oeis4.)