|
| |
|
|
A107347
|
|
Number of even semiprimes strictly between p and 2p.
|
|
0
| |
|
|
0, 1, 1, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7, 7, 8, 9, 9, 9, 9, 9, 10, 11, 11, 12, 13, 12, 13, 13, 14, 13, 14, 15, 15, 15, 16, 16, 17, 18, 19, 19, 20, 19, 18, 18, 19, 20, 21, 22, 23, 23, 23, 24, 25, 25, 25, 26, 27, 26, 27, 28, 28, 28, 28, 28, 29, 30, 30, 30, 31, 32, 32, 32, 32
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,6
|
|
|
MATHEMATICA
| fQ[n_] := Plus @@ Last /@ FactorInteger[n] == 2; f[n_] := Count[fQ /@ Range[Prime[n] + 1, Prime[n + 1] - 1], True]; Table[ f[n], {n, 78}] (from Robert G. Wilson v (rgwv(AT)rgwv.com), May 28 2005)
|
|
|
CROSSREFS
| Sequence in context: A057360 A057364 A060144 * A189717 A163127 A077113
Adjacent sequences: A107344 A107345 A107346 * A107348 A107349 A107350
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), May 23 2005
|
|
|
EXTENSIONS
| Corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), May 28 2005
|
| |
|
|
