|
|
A152758
|
|
Numbers k such that the deficiency of k plus the number of proper divisors of k is not a prime number (see A152864).
|
|
1
|
|
|
1, 8, 12, 15, 24, 25, 30, 32, 33, 35, 36, 39, 40, 42, 44, 48, 50, 51, 54, 56, 60, 63, 65, 66, 68, 69, 72, 78, 80, 81, 84, 85, 87, 90, 92, 96, 98, 100, 102, 105, 108, 112, 114, 116, 117, 120, 121, 123, 126, 128, 129, 130, 132, 136, 138, 140, 141, 143, 144, 148, 150, 153
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
MAPLE
|
with(numtheory): a := proc (n) if isprime(2*n-sigma(n)+tau(n)-1) = false then n else end if end proc: seq(a(n), n = 1 .. 200); # Emeric Deutsch, Jan 08 2009
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|