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A062955
a(n) = phi(n^2) - phi(n) = (n-1) * phi(n).
3
0, 1, 4, 6, 16, 10, 36, 28, 48, 36, 100, 44, 144, 78, 112, 120, 256, 102, 324, 152, 240, 210, 484, 184, 480, 300, 468, 324, 784, 232, 900, 496, 640, 528, 816, 420, 1296, 666, 912, 624, 1600, 492, 1764, 860, 1056, 990, 2116, 752, 2016, 980, 1600, 1224, 2704
OFFSET
1,3
LINKS
FORMULA
a(n) = A002618(n) - A000010(n). - Michel Marcus, Jun 28 2018
MATHEMATICA
Table[EulerPhi[n^2]-EulerPhi[n], {n, 60}] (* Harvey P. Dale, Aug 22 2012 *)
PROG
(PARI) a(n)=if(n<1, 0, eulerphi(n^2)-eulerphi(n))
(PARI) { for (n=1, 1000, write("b062955.txt", n, " ", eulerphi(n^2) - eulerphi(n)) ) } \\ Harry J. Smith, Aug 14 2009
CROSSREFS
Sequence in context: A088843 A154784 A328709 * A174932 A359103 A344223
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 22 2001
STATUS
approved