A069221 a(1) = a(2) = 1; a(n) = <>(a(n-1)) + <>(a(n-2)) for n > 2, where <>(k) denotes the concatenation of k with itself.

1, 1, 22, 2233, 22334455, 2233445544666688, 22334455446666884466891067001143, 2233445544666688446689106700114344668910893333766700336611667831

Offset

1,3

Links

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

Example

a(4) = <>(a(3)) + <>(a(2)) = <>(22) + <>(1) = 2222 + 11= 2233.

Crossrefs

Sequence in context: A046445 A133235 A114449 * A069222 A117990 A098130

Adjacent sequences: A069218 A069219 A069220 * A069222 A069223 A069224

Keyword

base,nonn

Author

Joseph L. Pe, Apr 12 2002

Status

approved