|
|
A189992
|
|
Numbers n such that 2^n'-1 is prime, where n' is the arithmetic derivative of n.
|
|
0
|
|
|
6, 10, 22, 30, 34, 58, 66, 118, 618, 730, 874, 1353, 2554, 2937, 7874, 7954, 8842, 11922, 12430, 15442, 17186, 26034, 115690, 166774, 170134, 221002, 264094, 368599, 1419045, 1443118, 1582026, 1583759, 1587721, 1829929, 1934249, 2053321, 2160359, 2207345
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
These numbers are the anti-derivatives of the Mersenne primes A000043. The prime 86243 has 11 anti-derivatives! - T. D. Noe, May 04 2011
|
|
LINKS
|
|
|
EXAMPLE
|
6'=5, 2^5-1=31 = prime -> a(1) = 6
|
|
MAPLE
|
last:=120: der:=n->n*add(op(2, p)/op(1, p), p=ifactors(n)[2]): seq(`if`(isprime(2^(der(i))- 1)=true, i, NULL), i=2..last);
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|