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 A091792 Concatenation of first n terms of A091791 divided by (2n-1). 2

%I

%S 1,4,243,17360,1350225,11047296,934771207,81013504612,7148250406947,

%T 6395802995689430,578667890086186528,52834894312217030820,

%U 48608102767239668354413,45007502562258952180012050

%N Concatenation of first n terms of A091791 divided by (2n-1).

%e a(1) = 1, a(2) = 12/3 = 4, a(3) = 1215/5 = 243.

%p A055642 := proc(n) ilog10(n)+ 1; end: Lcat := proc(L) local resul,i ; resul := op(1,L) ; for i from 2 to nops(L) do resul := resul*10^A055642(op(i,L))+op(i,L) ; od ; RETURN(resul) ; end: A091792 := proc(nmax) local a91,a,k,n ; a91 := [1] ; a := [1] ; for n from 2 to nmax do k :=1 ; while Lcat([op(a91),k*n]) mod (2*n-1) <> 0 do k := k+1 ; od ; a91 := [op(a91),k*n] ; a := [op(a),Lcat(a91)/(2*n-1)] ; od; a ; end: A091792(40); # _R. J. Mathar_, Jul 20 2007

%Y Cf. A091791.

%K base,nonn

%O 1,2

%A _Amarnath Murthy_, Feb 18 2004

%E More terms from _R. J. Mathar_, Jul 20 2007

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Last modified August 11 09:30 EDT 2020. Contains 336423 sequences. (Running on oeis4.)