|
| |
|
|
A159006
|
|
Transformation of prime(n): flip digits in the binary representation, revert the sequence of digits, and convert back to decimal.
|
|
0
| |
|
|
2, 0, 2, 0, 2, 4, 14, 6, 2, 8, 0, 22, 26, 10, 2, 20, 8, 16, 30, 14, 54, 6, 26, 50, 60, 44, 12, 20, 36, 56, 0, 62, 110, 46, 86, 22, 70, 58, 26, 74, 50, 82, 2, 124, 92, 28, 52, 4, 56, 88, 104, 8, 112, 32, 254, 62, 158, 30, 174, 206, 78, 182, 102, 38, 198, 134, 90, 234, 74, 138, 242
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Write the n-th prime in binary as in A004676. Change all 0's to 1's and all 1's to 0's to reach A145382. Read the binary digits from right to left. a(n) is the decimal equivalent of the result.
All entries are even, i.e., members of A005843.
|
|
|
EXAMPLE
| 37->100101->change digits 011010->read from right to left 010110->22 281->100011001->change digits 011100110->read from right to left 011001110->206
|
|
|
MAPLE
| P:=proc(i) local a, b, j, k, n; for n from 1 by 1 to i do a:=convert(ithprime(n), binary); j:=length(a); b:=convert(a, string); k:=""; while j>0 do if substring(b, j)="1" then k:=cat(k, "0"); else k:=cat(k, "1"); fi; j:=j-1; od; a:=convert(k, decimal, binary); print(a); od; end: P(100);
|
|
|
CROSSREFS
| Cf. A145382, A098957.
Sequence in context: A163169 A097974 A139036 * A171700 A162660 A090330
Adjacent sequences: A159003 A159004 A159005 * A159007 A159008 A159009
|
|
|
KEYWORD
| easy,nonn,base
|
|
|
AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), Apr 02 2009
|
|
|
EXTENSIONS
| Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 06 2009
|
| |
|
|
