|
| |
|
|
A066231
|
|
Numbers n such that EulerPhi(n) = EulerPhi(n-1)-EulerPhi(n-2).
|
|
2
|
|
|
|
6, 8, 26, 78, 218, 306, 3666, 4646, 5066, 8816, 12206, 12546, 19878, 20436, 24236, 29546, 37736, 47996, 60116, 72086, 73026, 77046, 87476, 121146, 126056, 129246, 149756, 190268, 234636, 247856, 273296, 275724, 419366, 531236, 553476, 621726
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Question: Are all terms of this sequence even? (Compare A065557, whose terms could be all odd and squarefree.)
|
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,117
|
|
|
EXAMPLE
|
EulerPhi(8) = 4 = 6-2 = EulerPhi(7)-EulerPhi(6).
|
|
|
PROG
|
(PARI) { n=0; for (m=3, 10^9, if (eulerphi(m) == eulerphi(m - 1) - eulerphi(m - 2), write("b066231.txt", n++, " ", m); if (n==117, return)) ) } [From Harry J. Smith, Feb 06 2010]
|
|
|
CROSSREFS
|
Cf. A067701.
Sequence in context: A219191 A107366 A024873 * A007829 A000773 A039720
Adjacent sequences: A066228 A066229 A066230 * A066232 A066233 A066234
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Dec 18 2001
|
|
|
EXTENSIONS
|
a(24) - a(36) from Harry J. Smith, Feb 06 2010
|
|
|
STATUS
|
approved
|
| |
|
|
