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 A235460 a(1)=2. For n>1, assume a(n-1) has decimal expansion abcdefghij (with at most ten digits, where some of j,i,h, ... may be missing). Then a(n) = sum 11...1 (with a 1's) + 22...2 (with b 2's) + 33...3 (with c 3's) + ... 1

%I

%S 2,11,3,111,6,111111,21,13,223,366,555666,1733331,2224228

%N a(1)=2. For n>1, assume a(n-1) has decimal expansion abcdefghij (with at most ten digits, where some of j,i,h, ... may be missing). Then a(n) = sum 11...1 (with a 1's) + 22...2 (with b 2's) + 33...3 (with c 3's) + ...

%C See A235400 for the analogous sequence where we number the digits starting with 9 at the rightmost digit.

%D Rodolfo Kurchan, Problems with repdigits, to appear in Proceedings of Gathering for Gardner 2014 conference

%e 2 means two 1's = 11; 11 means one 1 + one 2 = 3; 3 means 111; 111 means 1+2+3 = 6; 6 means 111111 = 1+2+3+4+5+6 = 21; 21 means 11+2 = 13; etc.

%Y Cf. A235400.

%K nonn,base

%O 1,1

%A _Rodolfo Kurchan_, Jan 10 2014

%E Edited by _N. J. A. Sloane_, Jan 24 2014

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Last modified September 24 21:05 EDT 2021. Contains 347651 sequences. (Running on oeis4.)