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

1, 4, 243, 17360, 1350225, 11047296, 934771207, 81013504612, 7148250406947, 6395802995689430, 578667890086186528, 52834894312217030820, 48608102767239668354413, 45007502562258952180012050

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

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

Maple

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

Crossrefs

Cf. A091791.

Sequence in context: A152793 A042769 A332124 * A300595 A320418 A090602

Adjacent sequences: A091789 A091790 A091791 * A091793 A091794 A091795

Keyword

base,nonn

Author

Amarnath Murthy, Feb 18 2004

Extensions

More terms from R. J. Mathar, Jul 20 2007

Status

approved