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A300950
Fixed points of A300948.
1
3, 4, 7, 8, 11, 12, 15, 48, 51, 52, 55, 56, 59, 60, 63, 64, 67, 68, 71, 72, 75, 76, 79, 112, 115, 116, 119, 120, 123, 124, 127, 128, 131, 132, 135, 136, 139, 140, 143, 176, 179, 180, 183, 184, 187, 188, 191, 192, 195, 196, 199, 200, 203, 204, 207, 240, 243
OFFSET
1,1
COMMENTS
This sequence contains A007013(k) for any k > 0.
We can devise a set of primitive fixed points of A300948, say P, as follows:
- P contains the powers of 2, say 2^i, such that A300948(2^i) = 2^i (in that case, i = a(k)-1 for some k > 0),
- and the sums of two distinct powers of 2, say 2^i + 2^j, such that A300948(2^i) = 2^j,
- we can uniquely write any term of this sequence as a sum of distinct terms of P.
FORMULA
For any n > 0 with binary expansion Sum_{i=0..k} b_i * 2^i, a(n) = Sum_{i=0..k} b_i * p(i+1) (where p(i) denotes the i-th term of the set P described in the Comments section).
EXAMPLE
A300948(7) = 7 hence 7 belongs to this sequence.
A300948(42) = 25 hence 42 does not belong to this sequence.
CROSSREFS
Sequence in context: A188259 A058235 A107819 * A368083 A067186 A133675
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 16 2018
STATUS
approved