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%I #28 Mar 17 2023 11:15:33
%S 12,34,56,78,910,1112,1314,1516,1718,1920,2122,2324,2526,2728,2930,
%T 3132,3334,3536,3738,3940,4142,4344,4546,4748,4950,5152,5354,5556,
%U 5758,5960,6162,6364,6566,6768,6970,7172,7374,7576,7778,7980,8182,8384,8586
%N Pair up the numbers.
%C That is, a(n) is the concatenation of 2n-1 and 2n. - _Charles R Greathouse IV_, Aug 07 2012
%H Vincenzo Librandi, <a href="/A030655/b030655.txt">Table of n, a(n) for n = 1..1000</a>
%t FromDigits[Flatten[IntegerDigits/@{#}]]&/@Partition[Range[90],2] (* _Harvey P. Dale_, Sep 28 2011 *)
%o (Magma) [Seqint(Intseq(n+1) cat Intseq(n)): n in [1..86 by 2]]; // _Bruno Berselli_, Jun 18 2011
%o (PARI) a(n)=eval(concat(Str(2*n-1),2*n)) \\ _Charles R Greathouse IV_, Jun 18, 2011
%Y Cf. A030656.
%Y Subsequence of A005843.
%K base,nonn,easy
%O 1,1
%A _Maghraoui Abdelkader_
%E More terms from _Erich Friedman_.