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 A081857 Jacobsthal sequence (A001045) as represented in base 4. 2
 0, 1, 1, 3, 11, 23, 111, 223, 1111, 2223, 11111, 22223, 111111, 222223, 1111111, 2222223, 11111111, 22222223, 111111111, 222222223, 1111111111, 2222222223, 11111111111, 22222222223, 111111111111, 222222222223, 1111111111111 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Eric Weisstein's World of Mathematics, Repunit. FORMULA For n > 0, a(2n) is represented as a string of n 1's and a(2n+1) as a string of (n-1) 2's followed by a 3. EXAMPLE a(8)= 1111 because A001045(8)= 85 (in base 10) = 64 + 16 + 4 + 1 = 1 * (4^3) + 1 * (4^2) + 1 * (4^1) + 1. CROSSREFS Cf. A002450. Sequence in context: A158034 A002515 A096297 * A168163 A120088 A081737 Adjacent sequences:  A081854 A081855 A081856 * A081858 A081859 A081860 KEYWORD base,easy,nonn AUTHOR Matthew Vandermast, Apr 11 2003 STATUS approved

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Last modified April 21 20:03 EDT 2019. Contains 322328 sequences. (Running on oeis4.)