|
Search: id:A064893
|
|
|
| A064893 |
|
Smallest number with "binary potency" of n. Blocks of at least n 0's must be inserted between the bits of a(n) to "dilute" it into a nonprime. |
|
+0
3
|
| |
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Are there values for all a(n)? Is the sequence monotonic?
|
|
EXAMPLE
|
1 is nonprime (potency 0) so a(0) = 1; 2 = 10 -> 0100 = 4, potency 1, so a(1) = 2; 3 = 11 -> 0101 = 5 -> 001001 = 9, potency 2 so a(2) = 3; potency 4 first appears for 29, so a(4) = 29; etc
4088027 dilutes into 5858670956869, 10540679875665334793, 20632314388123853242044433, 41873360515671700575496732442657 and 86420918502629375433474712237244678209, all prime. But the next dilution, 179810732934100666625066494484898891551473793, is composite.
|
|
CROSSREFS
|
Cf. A000040, A064891, A064892.
Sequence in context: A116325 A053998 A144953 this_sequence A141514 A078727 A076977
Adjacent sequences: A064890 A064891 A064892 this_sequence A064894 A064895 A064896
|
|
KEYWORD
|
base,nonn,nice
|
|
AUTHOR
|
Marc LeBrun (mlb(AT)well.com), Oct 10 2001
|
|
EXTENSIONS
|
a(6) from Don Reble djr(AT)nk.ca and Fred W. Helenius fredh(AT)ix.netcom.com, Oct 11, 2001. a(7) from Hans Havermann (pxp(AT)rogers.com), Oct 13, 2001
|
|
|
Search completed in 0.002 seconds
|
