A165195 Rows of triangle A165194 tend to this sequence; generated from A000110.

1, 1, 2, 1, 2, 5, 2, 1, 2, 5, 15, 5, 2, 5, 2, 1, 2, 5, 15, 5, 15, 52, 15, 5, 2, 5, 15, 5, 2, 5, 2, 1

Offset: 1

Author

Gary W. Adamson, Sep 06 2009

Keywords

• nonn

Examples

			Given terms in the Bell sequence, A000110; A165195 begins (1, 1, 2, 1,... then to obtain the first 2^3 terms, the first 2^2 terms = (1, 1, 2, 1,... then append to the latter the reversal of (1, 1, 2, 1) = (1, 2, 1, 1) but incremented with the next higher Bell number = (2, 5, 2, 1). The first 2^3 terms are thus (1, 1, 2, 1, 2, 5, 2, 1). Repeat with analogous operations to obtain 2^4 terms, and so on..
		

Crossrefs

Cf. A000110, A165194, A165196.

Formula

The sequence can be generated from strings of 2^n terms starting (1, 1,... then the next string of 2^(n+1) terms is obtained by appending a "reverse and increment" substring to the previous substring.