A158859 a(n) is formed by 2n+1 concatenations of the digit 2r+1 where n=r (mod 5).

1, 333, 55555, 7777777, 999999999, 11111111111, 3333333333333, 555555555555555, 77777777777777777, 9999999999999999999, 111111111111111111111, 33333333333333333333333

Offset

0,2

Comments

One 1, three 3's, five 5's, seven 7's, nine 9's, eleven 1's, thirteen 3's,

Links

Table of n, a(n) for n=0..11.

Crossrefs

Cf. A158849.

Sequence in context: A250835 A378893 A221827 * A367978 A182098 A331411

Adjacent sequences: A158856 A158857 A158858 * A158860 A158861 A158862

Keyword

nonn,base

Author

Paul Curtz, Mar 28 2009

Extensions

Definition modified by R. J. Mathar, Apr 06 2009

Status

approved