A336527 a(1) = 1; a(2) = 2; for n > 2, a(n) is the least number > a(n-1) whose binary representation is uniquely the concatenation of the binary representations of two distinct earlier terms.
1, 2, 5, 6, 11, 14, 21, 23, 26, 27, 29, 30, 47, 62, 85, 86, 87, 90, 95, 106, 107, 111, 117, 122, 125, 126, 171, 174, 183, 186, 187, 191, 219, 234, 237, 238, 239, 246, 251, 254, 341, 347, 349, 351, 363, 383, 426, 431, 442, 447, 470, 471, 474, 479, 491, 495, 501
Offset: 1
Examples
The first terms, alongside the binary representations of the natural numbers with the corresponding concatenations of distinct smaller terms, are:
n a(n) k bin(k) concatenations
- ---- -- ------ --------------
1 1 1 1
2 2 2 10
3 11
4 100
3 5 5 101 10|1
4 6 6 110 1|10
7 111
8 1000
9 1001
10 1010
5 11 11 1011 101|1
12 1100
13 1101 1|101, 110|1
6 14 14 1110 1|110
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..10000
- Rémy Sigrist, PARI program for A336527
Programs
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PARI
See Links section.
Comments