A229205 Lucky numbers generated from squarefree numbers.

1, 3, 10, 13, 19, 22, 30, 33, 38, 47, 53, 59, 69, 71, 78, 82, 87, 97, 107, 110, 115, 129, 138, 146, 151, 158, 161, 167, 173, 182, 187, 197, 210, 218, 223, 227, 233, 249, 255, 265, 267, 278, 285, 295, 299, 305, 314, 318, 327, 334, 346, 357, 367

Offset

1,2

Comments

Follow same procedure that is used to produce the lucky numbers A000959 but start with squarefree numbers A005117 instead of natural numbers.

Links

Table of n, a(n) for n=1..53.

Example

Start with squarefree numbers A005117 = (1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 29, 30,...).
Delete every second number to get (1,_ 3,_ 6,_ 10,_ 13,_ 15,_ 19,_ 22,_ 26,_ 30, ...).
Since the next larger remaining number is 3, delete every 3rd number, to get (1, 3,_ 10, 13,_ 19, 22,_ 30, ...).
The next larger remaining number is 10, so delete every 10th term, etc. Note that "30" will remain in this sequence, but is not among the squarefree numbers indexed by lucky numbers, A229483. - M. F. Hasler, Sep 24 2013

Prog

(PARI) list_A229205(Nmax)={my(v=(select(issquarefree, vector(Nmax, i, i))), i, k); while(v[i=k+++(v[k]==1)]<=#v, v=vecextract(v, 2^#v-1-sum(j=1, #v\v[i], 2^(v[i]*j-1)))); v} \\ M. F. Hasler, Sep 24 2013

Crossrefs

Cf. A059987, A032605, A229483.

Sequence in context: A188373 A190776 A298418 * A229483 A235089 A022122

Adjacent sequences: A229202 A229203 A229204 * A229206 A229207 A229208

Keyword

nonn

Author

Irina Gerasimova, Sep 16 2013

Status

approved