|
|
A178611
|
|
n-th semiprime minus sum of prime indices of the two factors of n-th semiprime.
|
|
0
|
|
|
2, 3, 5, 6, 9, 10, 15, 16, 19, 19, 26, 26, 28, 29, 31, 36, 41, 42, 47, 47, 47, 50, 56, 58, 61, 68, 68, 75, 71, 75, 81, 80, 78, 84, 89, 97, 103, 100, 108, 111, 103, 108, 113, 121, 114, 124, 121, 132, 132, 124, 141, 135, 141, 148, 142, 157, 158, 153, 163, 170, 175, 168
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
nn = 200; Sort[Reap[Do[n = Prime[i] * Prime[j] - i - j; If[n <= nn, Sow[n]], {i, PrimePi[nn/2]}, {j, i}]][[2, 1]]] (* T. D. Noe, Mar 16 2011 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|