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 A098752 a(1) = 1 and a(n+1) is the least number > a(n) that begins with the last digit of a(n) and doesn't end with 0. 0
 1, 11, 12, 21, 101, 102, 201, 1001, 1002, 2001, 10001, 10002, 20001, 100001, 100002, 200001, 1000001, 1000002, 2000001, 10000001, 10000002, 20000001, 100000001, 100000002, 200000001, 1000000001, 1000000002, 2000000001, 10000000001 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) must be chosen with nonzero rightmost digit. LINKS Table of n, a(n) for n=1..29. FORMULA For n == 0 (mod 3), a(n) = 10^(n/3) + 2; for n == 1 (mod 3), n>1, a(n) = 2*10^((n-1)/3) + 1; for n == 2 (mod 3), a(n) = 10^((n+1)/3) + 1. - Sam Alexander, Jan 04 2005 From Chai Wah Wu, Jun 02 2016: (Start) a(n) = 11*a(n-3) - 10*a(n-6) for n > 7. G.f.: x*(1 + x + 2*x^2)*(1 + 10*x - 10*x^3 - 10*x^4)/((1 - x)*(1 - 10*x^3)*(1 + x + x^2)). (End) a(n) = (1-sign((n-1) mod 3))*10^floor(n/3)+10^floor((n+1)/3)-sign(n mod 3)+2, for n > 1. - Wesley Ivan Hurt, Mar 06 2022 CROSSREFS Cf. A076654. Cf. A101233. Sequence in context: A131363 A089185 A098754 * A240763 A231871 A192287 Adjacent sequences: A098749 A098750 A098751 * A098753 A098754 A098755 KEYWORD base,easy,nonn AUTHOR Eric Angelini, Oct 01 2004 EXTENSIONS More terms from Sam Alexander, Jan 04 2005 More terms from David Wasserman, Feb 26 2008 STATUS approved

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Last modified June 1 17:30 EDT 2023. Contains 363076 sequences. (Running on oeis4.)