A098153 Summarize the previous term in binary (in increasing order).

1, 11, 101, 10101, 100111, 1001001, 1000111, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001, 1101001

Offset

1,2

Comments

Similar to A005151 but uses base 2: Let a(1)=1. Describing a(1) as "one 1" again gives a(2)=11 (same digit string as A005151 and similar sequences), but describing a(2) as "two 1's" gives a(3)=101 when the frequency of digit occurrence is written in binary and followed by the digit counted.

Links

Table of n, a(n) for n=1..27.

Formula

a(n) = 1101001 for all n >= 8 (see example).

Example

Summarizing a(8) = 1101001 in increasing digit order, there are "three 0's, four 1's", so concatenating 11 0 100 1 gives a(9) = 1101001 (=a(10)=a(11)=...).

Crossrefs

Cf. A098154 (ternary), A098155 (base 4), A005151 (decimal and digit strings for all other bases b >= 5).

Sequence in context: A080176 A064490 A080439 * A020449 A089971 A082620

Adjacent sequences: A098150 A098151 A098152 * A098154 A098155 A098156

Keyword

base,easy,nonn

Author

Rick L. Shepherd, Aug 29 2004

Status

approved