A007943 - OEIS

%I #25 Dec 23 2023 14:23:27

%S 12,1342,135642,13578642,13579108642,135791112108642,

%T 1357911131412108642,13579111315161412108642,

%U 135791113151718161412108642,1357911131517192018161412108642

%N Concatenation of sequence (1,3,..,2n-1,2n,2n-2,..,2).

%D M. Le, Perfect Powers in the Smarandache Permutation Sequence, Smarandache Notions Journal, Vol. 10, No. 1-2-3, 1999, 148-149.

%H Harvey P. Dale, <a href="/A007943/b007943.txt">Table of n, a(n) for n = 1..184</a>

%H F. Smarandache, <a href="http://www.gallup.unm.edu/~smarandache/OPNS.pdf">Only Problems, Not Solutions!</a>

%t Table[FromDigits[Join[Flatten[IntegerDigits/@Range[1,2n+1,2]],Flatten[ IntegerDigits/@ Range[2n+2,2,-2]]]],{n,0,10}] (* _Harvey P. Dale_, Jul 30 2021 *)

%Y Cf. A007942.

%K nonn,base

%O 1,1

%A R. Muller