A109667 Beginning with 1, a(n) = n times the digits of concatenation of a(1),a(2), ...a(n-1) read backwards.

1, 2, 63, 14484, 2422068105, 30111613454906481726, 4390292266180212777245130215697390895347, 59487847503720962523422176966532983367477017476875634528888280148817939875308968

Offset

1,2

Comments

a(9) has 160 digits, a(10) has 320 digits. - R. J. Mathar, Feb 13 2008

Links

Table of n, a(n) for n=1..8.

Example

a(2) = 2*1 = 2, a(3) = 3*21 = 63, a(4) = 4*3621 = 14484.

Maple

A109667 := proc(n) option remember ; if n = 1 then 1; else digs := [] ; for i from 1 to n-1 do digs := [op(digs), op(ListTools[Reverse](convert(A109667(i), base, 10))) ] ; od: n*add(op(i, digs)*10^(i-1), i=1..nops(digs)) : fi ; end: seq(A109667(n), n=1..9) ; # R. J. Mathar, Feb 13 2008

Crossrefs

Sequence in context: A239744 A024238 A234279 * A330059 A004853 A249073

Adjacent sequences: A109664 A109665 A109666 * A109668 A109669 A109670

Keyword

base,easy,nonn

Author

Amarnath Murthy, Aug 03 2005

Extensions

More terms from R. J. Mathar, Feb 13 2008

Status

approved