%I A001704
%S A001704 12,23,34,45,56,67,78,89,910,1011,1112,1213,1314,1415,1516,1617,1718,
%T A001704 1819,1920,2021,2122,2223,2324,2425,2526,2627,2728,2829,2930,3031,3132,
%U A001704 3233,3334,3435,3536,3637,3738,3839,3940,4041,4142,4243,4344,4445,4546
%N A001704 a(n) = concatenation {n,n+1}.
%F A001704 a(n)=n*10^{1+floor[log(n+1)]}+n+1, with n>=1 - Paolo P. Lava (ppl(AT)spl.at), 
               May 09 2008
%p A001704 P:=proc(n) local a,i; for i from 1 by 1 to n do a:=i*10^(1+floor(evalf(log10(i+1),
               10)))+i+1; print(a); od; end: P(100); - Paolo P. Lava (ppl(AT)spl.at), 
               May 09 2008
%Y A001704 See A127421 for another version.
%Y A001704 Sequence in context: A098953 A072485 A035333 this_sequence A127421 A112131 
               A088997
%Y A001704 Adjacent sequences: A001701 A001702 A001703 this_sequence A001705 A001706 
               A001707
%K A001704 nonn,base,easy
%O A001704 1,1
%A A001704 N. J. A. Sloane (njas(AT)research.att.com).
%E A001704 More terms from Joshua Zucker (joshua.zucker(AT)stanfordalumni.org) and 
               Jon E. Schoenfield (jonscho(AT)hiwaay.net), May 15 2007